VLAN Forwarding Modes and IB
Short Description
How to associate rb vlan ethernet ports...
Description
University VLAN forwarding modes and IB
7302-7330-735x ISAM / 5520 AMS operator part 1 section D
Alcatel-Lucent University Antwerp 1
Alcatel-Lucent University Antwerp
During class please switch off your mobile, pager or other that may interrupt. Entry level requirements: > You are familiar with the theoretical concepts of Ethernet and VLANs. > You can configure equipment and interworking function(basic configuration) on ISAMs using the 5520AMS.
TAC03001 _D Ed01
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© 2008 Alcatel Bell N.V., All rights reserved
Objectives After attending this session, you should be able to: Describe what a Residential Bridge VLAN (= Intelligent Bridge VLAN) is Explain how the RB-VLAN is behaving on LT on SHUB
Create a RB-VLAN via AMS and CLI on ASAM-CORE on service hub
Associate a RB-VLAN to Ethernet ports on the service hub Associate a RB-VLAN to a bridge port with or without VLAN translation
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© 2008 Alcatel Bell N.V., All rights reserved
Table of contents Forwarding modes: general
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p. 4
Layer 2 forwarding: The Basics
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p. 7
Intelligent bridging .
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p. 15
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p. 33
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p. 47
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p. 61
VLAN setup .
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VLAN association Exercises
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© 2008 Alcatel Bell N.V., All rights reserved
University Forwarding modes
General
Alcatel-Lucent University Antwerp
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© 2008 Alcatel Bell N.V., All rights reserved
Forwarding engines On the LT On the NT the forwarding engine is part of the service hub x/Eth
x/Eth NT
LT 1
x/Eth
IWF
FW Engine
x/Eth
GE1-16
ASAM link
FW Engine
GE/FE 1-7
LT x Forwarding Engine
External Ethernet links
Service Hub
x/Phys layer
EFM / user port
PVC / Logical user port
x/ATM/Phys. Layer
x/Eth
CPE
CPE
x/Eth
5
> We mentioned earlier that the LT contains the Inter Working Function and the service hub (that is hosted on the NT) the aggregation function. Both of them perform forwarding, and for that purpose, the Inter Working Function provides a forwarding engine (i.e. a bridge).
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© 2008 Alcatel Bell N.V., All rights reserved
Forwarding modes: General 7302 ISAM
L3 L2+ L2
Network side
User side
Eth-VLAN ANT
Decision
Forwarding mode
L2
Intelligent Bridge (IB) VLAN Cross-Connect (CC) Enhanced iBridge
L2+
PPPoE Engine
L3
Routed
6
> Different forwarding modes are supported in order to make it fit into different network models of different operators. > If the DSLAMs are mainly connected to a bridged Metro Ethernet network, the MAC scalability may become an issue when only layer 2 forwarding is done in the DSLAM. In that case the MAC addresses of all end-user terminals will have to be learnt in the MetroEthernet network, while the MAC tables of some bridges may be quite limited. In that case, it would probably be better to use the layer 2+ or L3 forwarding function of the ISAM. (However, we mustn’t exaggerate this issue: most bridges can learn many MAC-addresses without any problem!) > However, if IP routers are used in the Metro Ethernet Network close to the DSLAMs, MAC scalability will not be an issue, and layer 2 forwarding in the DSLAM may be an interesting option, because in general layer 2 means less configuration effort. With 7302 ISAM, operators have the flexibility to choose the forwarding mode which best fits in their network. > In general, the previous layer 2 and layer 3 forwarding functions are an overkill for networkVPN services towards business customers, given the number of connections to the same VPN from one DSLAM will be mostly only one, or only very few connections per VPN. In such cases, the VLAN cross-connect mode of the ISAM is much more appropriate for these business users: • less configuration effort, • avoid too many bridges or routers in one VPN.
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© 2008 Alcatel Bell N.V., All rights reserved
University L2 Forwarding mode
Alcatel-Lucent University Antwerp
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© 2008 Alcatel Bell N.V., All rights reserved
General overview 7302 ISAM Network side
Anything Eth - VLAN
L2
Anything Eth – (VLAN) ATM/AAL Phys layer
Anything Eth – (VLAN) Phys layer
User side
Eth-VLAN
layer 2 forwarding Ethernet layer must be present at both sides. encapsulation at CPE must include Ethernet
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> In case the 7302 ISAM performs L2 forwarding, it means that the internal forwarding is basically done on layer 2 information. The layer 2 is Ethernet, including the concept of VLANs. > In both layer 2 forwarding models (intelligent bridge as well as cross-connect), the ISAM can accept tagged frames coming from a user. The operator can configure exactly which tag is to be expected on the bridge port and frames carrying another tag will be discarded (filter). > In case of VLAN translation, the user sends tags that are recognized, but only have a local meaning and will immediately be translated into a network vlan. > In case of cross-connect, it is possible to have C-VLAN transparency (where only the S-VLAN is configured in the ISAM). In that case, the user can send no matter what C-VLAN. The ISAM will not filter based on C-VLAN. See section on cross-connect.
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© 2008 Alcatel Bell N.V., All rights reserved
Two L2 forwarding modes the intelligent bridging (IB): one (or more) circuits per VLAN Forwarding based upon MAC addresses and VLAN
the cross-connect (CC): one (or more) VLANs per circuit Forwarding based upon User side: – bridge port on PVC for ATM or – (subscriber VLAN on) bridge port on DSL port for EFM Network side: Single or stacked VLAN tag
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> The ISAM 7302 provides a special Layer 2 behavior that results from being deployed in an access environment. I.e. it supports the 'cross connect mode' and it supports the 'Intelligent Bridging mode'. > In cross-connect mode, a particular VLAN-id is associated to one user connection only. > In intelligent bridging mode, multiple user connections can be associated with each virtual LAN. > The mode can be configured per VLAN. A particular VLAN can operate in only one of these modes at a time. A port however can be assigned to one or more VLAN cross-connects at a time and can therefore operate simultaneously in cross-connect or intelligent bridging mode. This is especially true for the Ethernet port, since it must belong to every VLAN configured.
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© 2008 Alcatel Bell N.V., All rights reserved
L2 functionalities
NT External Eethernet links
Control/Mgt function Control link
LT 16
ASAM link
FE
Aggregation function
GE/FE 1-7 GE1 ..16
IWF ASA
Service Hub GE1-16
Standard VLAN enabled bridge.
Ml
ink
LT 1 U S E R
IWF
Special VLAN enabled bridge. PVC / Logical user port
P O R T S
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> In general the aggregation function implemented by means of the Service Hub, on the NT, behaves as a standard bridge. A few extra features make that the Service Hub can be configured to behave in the IB mode or XC mode. > The Service Hub (Ethernet Switch) is composed of: 1) the Ethernet transceiver function 2) the Forwarding Engine, providing the Ethernet L2 switching function 3) the switch, providing network (trunk) ports, cascade / subtending (trunk) ports, user Ethernet ports, NT(control) Ethernet port (on ECNT-A only!), Out-band management Ethernet port and ASAM (LT) Ethernet ports. > It is the IWF (Interworking Function) on the LT board that serves as the ATM to Ethernet interworking device. > In the upstream direction (ingress bridge port on ATM PVC port), the IWF on the LT receives traffic on the ATM PVC port, reassembles the Ethernet frames from the ATM cells and forwards them towards theSHUB and thus to the E-MAN network. > In the downstream direction the network interface of the Service Hub receives the Ethernet frames and forwards them towards the correct egress port on the Service Hub. Once the Ethernet frame is received on the ingress Ethernet port of the IWF, the frame is forwarded towards the correct user logical port where the received Ethernet frames are segmented into ATM cells and forwarded toward the correct ATM PVC ports. > The Service Hub and the IWFs on the LTs behave (as much as possible) as two independent Layer 2 systems: they both will learn and age independently on MAC addresses. > The control function is involved in the management of the data plane.( see later)
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© 2008 Alcatel Bell N.V., All rights reserved
ISAM
GE E-MAN Network
POTS,ISDN
NT
LT CPE
Anything
Anything Ethernet Layer 2
ETH-ATM Ethernet Interworking Ethernet Layer 2 Layer 2Function
(+ MAC Control)
(+ MAC Control)
(IWF)
EthSwitchEth PHY
PHY
FE/GE
EthSwitchEth FE/GE
GE
GE
LLC SNAP
Ethernet Layer 2 LLC SNAP
AAL5
AAL5
ATM
ATM
PHY
xDSL?
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> The customer’s CPE is connected to the ASAM-Core with an ATM interface. It is the IWF on the LT that provides the interworking between the ATM and the Ethernet/VLAN technology. The Service Hub will behave as a standard bridge with some enhancements and perform layer 2/Ethernet forwarding > The layer 2 access offered via the IWF does not offer the same capabilities as the traditional ATM Layer 2 access offered by the ASAM. A traditional ATM Layer 2 access network is transparent for everything on top of ATM and as such supports many more frame encapsulation techniques at the CPE. The proposed E-MAN/ATM layer 2 access supports only CPEs using Ethernet over ATM, encapsulated by AAL5 and RFC2684 “bridged” > In the case that the 7302 ISAM performs layer 2 forwarding and the Ethernet switches in between (EMAN) are working as bridges. In that case the Ethernet L2 environment is terminated in the IP edge (typically the BRAS).
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© 2008 Alcatel Bell N.V., All rights reserved
University Intro Standard Bridging
Alcatel-Lucent University Antwerp
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© 2008 Alcatel Bell N.V., All rights reserved
Standard bridging concept MAC bridges can interconnect all kinds of LANs together No guaranteed delivery of frames A bridge learns MAC addresses Flooding occurs when destination MAC address is broadcast, multicast or unknown, : “If you do not know, send it to everybody’
If the destination MAC address has been learned, the frame is forwarded to the indicated interface
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© 2008 Alcatel Bell N.V., All rights reserved
Security/scalability issue with standard bridging Broadcast frames (ARP, PPPoE-PADI…) forwarded to all users & flooding to all ports. MAC-address of a user is exposed to other users Broadcast storms Ethernet
BC or unknown MAC DA
BR CPE
BRAS
DSLAM
BC or unknown MAC DA
CPE
PC
PC
PC
CPE DSLAM 14
> The issue on the slide occurs with standard Ethernet bridges. Operators using VPLS in the EMAN will not have this issue!
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© 2008 Alcatel Bell N.V., All rights reserved
Standard bridging: Issues Broadcast storms Security Broadcast frames are forwarded to all users
Customers identified by MAC-address (not guaranteed unique) Restrictions on services and revenues: IP edge device has no info on the access line So not possible to limit the # of sessions per access line
User-to-user communication possible without passing the BRAS
NOT FIT FOR USE IN PUBLIC NETWORKS
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> Scalability: • Broadcast storms – Broadcast frames are flooded over the entire aggregation network . This generates an important amount of traffic, that can result in service degradation or denial of service – Bridges have to learn MAC-addresses of all devices connected to the network > Security • Broadcast frames (ARP, PPPoE - PADI, …) are forwarded to all users – MAC-address of a user is exposed to other users > Customer segregation • customers are identified by MAC-address, and MAC-addresses are not guaranteed unique – undesirable & unstable behaviour: user B gets traffic destined to user A and vice versa. > PADI = PPPoE Active Discovery Initiation packet (which is broadcasted). This is the first message in the initialization phase to establish a PPPoE session.
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© 2008 Alcatel Bell N.V., All rights reserved
University Intelligent Bridging
Alcatel-Lucent University Antwerp
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© 2008 Alcatel Bell N.V., All rights reserved
The intelligent bridging model (1/3) Multiple users connected to 1 VLAN ID
Note: Tagged frames not supported for IB if Rel. In case of Intelligent bridging multiple users are connected to the same VLAN, or in other words we have aggregation at DSLAM level within a VLAN. > In the figure at the left we see multiple VLAN bridges supported in 1 DSLAM, to connect to different Service Providers (SP) (wholesale). Each SP is connected to the DSLAM with a specific VLAN-ID. The user ports are connected to the VLAN of their corresponding SP. Multiple user ports can be associated to a single VLAN-ID. Users 2 and 5 are connected to the ISP1 VLAN Users 1, 3 & 4 are connected to the ISP2 VLAN. The MAC address lookup is performed in the forwarding table of the respective VLAN. With the principle that we have 1 VLAN ID per {IP-edge-DSLAM} pair this means that in each Ethernet switch the SP has its own forwarding table. > In the figure at the right we see that the routing to the correct SP is based on user-id and password and that all the users are connected with the same VLAN-ID to the BRAS.
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© 2008 Alcatel Bell N.V., All rights reserved
The intelligent bridging model (2/3) Why VLAN Translation (customer vlan to network vlan) Wholesale per service Drivers: VDSL and Eth offer more BW, so it makes sense to wholesale this “in pieces” rather than the complete DSL line as a whole Consequences: Model with VLANs on DSL line; behaviour equivalent to multi-VC model on ATM/ADSL
VLAN per service and per provider in the aggregation network Service provider is free to choose CPE configuration, but VLANs in aggregation network are under control of ILEC
Ultimately 1 subscriber (1 line) may have to support 2 HSIA services or 2 video services from different service providers.
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> There are many operators who base their network architecture on one PVC per service when connecting ADSL subscribers. Once those operators start deploying VDSL, they are immediately confronted with the issue, that their is no similar approach for EFM interfaces. That’s why we have introduced VLAN Translation. > Requirement is driven by the wholesale model. Operators wants to use a network model whereby a given user can be subscribed to a different service provider for each service. Therefore they want to have separate "circuits" per service all the way up to the CPE. They are looking at a model of VLAN/service on the DSL line, and VLAN/service/ISP in the aggregation network.
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© 2008 Alcatel Bell N.V., All rights reserved
The intelligent bridging model (3/3) Special layer 2 behavior needed in an access environment IB with VLAN tagging
Intelligent Bridge (IB) means distinction between network ports and user ports Frames from a user always sent towards the network – No user to user communication
prevent broadcast traffic from escalating avoid broadcast or flooding to all users
secure MAC-address learning within a VLAN avoid MAC-address duplication over multiple ports
protocol filtering may lead to a frame being forwarded, sent to a host processor, discarded or forwarded & sent to a host processor
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> In a standard bridge all ports are treated equally. The special thing about Intelligent Bridging is that it makes a distinction between network ports and user ports. > With Intelligent Bridging, frames received from a user will always be sent towards the network and never to another user. All traffic received from a user interface is forwarded only on the uplink, and never to other users. This avoids that a user's MAC-address is exposed to other users; and also assures that user's traffic is passing through the IP edge point where it can be charged for. • Unicast frames: user-to-user communication is not permitted. • Broadcast and multicast frames from a user are only forwarded to the interface towards the network and not to all other users. > A second difference with standard bridging is the prevention of broadcast storms: In a standard bridge, a broadcast frame will be sent to all ports in a particular VLAN. In case of a Intelligent Bridging this is no longer true. Depending on the type of broadcast frame (depending on the protocol above Ethernet e.g. DHCP) the treatment will be different. Each protocol will deal with the restriction of Intelligent Bridging in a different way. In all cases a broadcast to all users is avoided. E.g. Broadcast as a consequence of flooding (when the MAC DA is unknown) or in case of multicast. > Another difference with standard bridging is the way how MAC addresses are learnt: protection is built in to avoid the use within one particular VLAN of the same MAC address over multiple ports. > With intelligent bridging only the following types of frames are accepted from the user ports: IPv4, ARP, PPPoE, IGMP and EAPOL (used for 802.1x). Other frames will be discarded, including multicast data frames coming from user ports.
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© 2008 Alcatel Bell N.V., All rights reserved
Intelligent bridging: network issues
BR VLAN1 CPE ISAM
IP edge Ethernet
Problem: If user A can obtain the MAC@ of User C, since the Ethernet switch learns all Mac @ , user to user communication is possible
CPE
ISAM
MACA
MACB
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> On the previous slides, we learnt how user to user communication is avoided inside the ISAM. But it is also important to mention that a VLAN must be unique between an [IP-edge-ISAM]pair in the Ethernet network to support the Intelligent Bridging feature. Take e.g. the network configuration shown in the figure above, where 2 ISAMs with same VLAN are connected to the IPedge via the EMAN network through a single VLAN. Or in other words a single VLAN exists between ISAM1, ISAM2, and the IP-edge). > In this case, the Ethernet switch learns all user MAC addresses and if user A can obtain the MAC address of user C, then user A can send traffic directly to user C without going to the IPedge. This is not acceptable: in Intelligent Bridging mode no direct user to user communication is allowed in the network. Another issue is that in such configuration an ISAM would receive all broadcast / flooded frames from any ISAM in the VLAN, with potential performance issues as a consequence.
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© 2008 Alcatel Bell N.V., All rights reserved
Broadcast messages & flooding US Upstream BC frames & flooding only forwarded towards network port(s) within a VLAN 1 VLAN per IP-edge Reduction of flooding in the aggregation network. No user-to-user communication without passing the BRAS BC or unknown MAC DA VLAN 1
Ethernet
BR
VLAN 2
BRAS
ISAM
CPE
CPE
☺
ISAM
PC A
PC B PC
CPE 21
> Blocking user to user communication at L2 > The principle is to avoid that 2 users connected to the same ISAM will communicate with each other directly at L2. In this case, when user A sends a message with destination MAC-address B, that message is sent to the uplink, not to user B. In case of PPP this is not an issue, since all messages coming from the DSL users will have destination MAC-address = MAC-address of the BRAS > The objective is that all traffic passes a L3 box. The motivation is twofold: • Security: If direct user-to-user communication at L2 would be allowed, this would give malicious users an easy way to find out the MAC address of other users, and then try to take it over. Note: blocking duplicate MAC-addresses will solve most of it, but if the malicious user is waiting until the MAC-address has aged, and then tries to take it for himself, he blocks the other user. • Accounting for traffic: If we would allow for user to user communication directly in the ISAM, we would also have to introduce mechanisms to measure and account for the traffic. Not just for billing purposes (most services will likely not use volume-based billing), but also for features such as legal intercept. So in other words, this kind of peer-to-peer traffic would be “hidden” to the operator, and in particular for peer to peer traffic operators will probably not like that.
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© 2008 Alcatel Bell N.V., All rights reserved
Broadcast messages & flooding DS Blocking of broadcast & flooding in the downstream Avoids messages unintentionally distributed to all users For some applications forwarding of BC is “needed” Solution: Make BC flooding / BC discarding a configurable option per VLAN Ethernet
BR CPE ISAM
BRAS
☺
PC
BC or unknown MAC DA
CPE
CPE ISAM
PC
PC
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> In a normal bridge when a message is received with a destination MAC-address not yet in the self-learning table, the message is broadcast to all the other interfaces. Also broadcast messages are flooded to all interfaces In an Intelligent bridge you want to avoid that in the downstream, messages are unintentionally distributed to all users. Therefore you need to put mechanisms in place that together with the systems set up in the upstream, will inhibit BC messages to be sent to all users and avoid the flooding of messages with unknown MAC DA to all users. > For some applications it is useful that flooding BC is possible. A solution for these applications is e.g. to make flooding BC/discarding BC a configurable option per VLAN.
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© 2008 Alcatel Bell N.V., All rights reserved
Intelligent Bridge Bridge: learning, aging, forwarding lookup MAC DA done based on VLAN and MAC-address intelligent bridging enhancements implemented on ISAM
LT and SHUB have independent MAC-address learning independent MAC-address aging aging timers are configurable
[10...1000000] sec
Recommended default value is 300 sec
aging timer per VLAN aging timers are configurable Default value –1
[-1,10...1000000] sec
use system Aging timer on LT
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> The Service Hub and the LTs autonomously learn MAC addresses. They also autonomously age on these MAC addresses. Aging timers are configurable. The idea is that the Service Hub is configured with the same aging timer than the one of the IWF of the LT. This is needed to avoid conflicts, e.g. when the MAC address is aged on the Service Hub, then the Service Hub could learn the MAC address on another interface with unpredictable behavior as a consequence. Once a MAC address is aged, then no downstream communication is possible until the address is learnt again in the upstream direction. > So it’s important that the MAC ageing time is properly configured, otherwise data-plane connectivity may be lost between the network and the ISAM end-users (nightly SW download on STB, incoming VoIP calls, …) – In case of PPPoE traffic the MAC aging time can be kept small, because PPP has a built-in keep-alive mechanism – In case of DHCP-based service scenario's, the MAC ageing time must be taken in the same order of magnitude as the DHCP lease time
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© 2008 Alcatel Bell N.V., All rights reserved
IB Configuration of SYSTEM and/or per VLAN aging timer
LT
Si de
UB SH e sid
Pe rV LA N
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> CLI Commands: System aging timers IACM and SHUB • Configure bridge ageing-time [10...1000000] • Configure bridge shub ageing-time [10...1000000] > CLI Command: MAC aging PER VLAN (IACM) • Configure vlan id 200 aging-time [-1,10...1000000]
Default value –1
TAC03001 _D Ed01
IACM system settings are used.
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© 2008 Alcatel Bell N.V., All rights reserved
LT self-learning only in the upstream - when initiated from user logical port Self-learning can be disabled per user logical port. In case of self-learning, limiting number of MAC addresses is possible.
NO selflearning
Learning of Source Mac@ within VLAN MacA
LT
x
To Service Hub
y z
MacB
MacC
25
> We call the LT IWF half a bridge as it only learns MAC addresses in the upstream direction. This has as a consequence that no connection can be initiated from the network side if the MAC address on the user side is not known or has not been learned yet.
TAC03001 _D Ed01
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© 2008 Alcatel Bell N.V., All rights reserved
Self learning in the Service Hub Self-learning implemented for both upstream and downstream Discard all user unicast frames with MAC DA known on an ASAM or subtending port No user to user communication Learning of Source Mac@ within VLAN Service Hub E-MAN
U’ Y’
E-MAN
LT
X’
V’
Z’
MacA
MacB
LT
B B
A C
LT
MacC
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© 2008 Alcatel Bell N.V., All rights reserved
Blocking of user to user communication
Port mapping on the service hub/NT An interface can only communicate with its mapping ports
Control link
8 Network links
Control link
X Network links
Service Hub
Service Hub
User links
1
15
16
1
ASAM links
15
16
subtending link
ASAM links
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> This is what prevents user-to-user communication when users are on different LTs.
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© 2008 Alcatel Bell N.V., All rights reserved
Port mapping Port mapping is used to … block user to user communication on the service hub NT
Control link LT
E-MAN network links ASAM links
LT
subtending links user links
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> It is possible that a VLAN used to transport user frames will contain ASAM/ subtending / user interface(s) and a network interface(s) or even more ASAM interfaces and subtending interfaces …. Possibly also both an ASAM and a subtending interface can be present in the same VLAN. The question arrises how we prevent user to user communication within the same VLAN > The blocking of user-to user communication on the Service Hub is provided by port mapping > This way we allow L2 bi-directional communication with supporting tagged frames (within the same VLAN) only between network ports and ASAM ports, between network ports and subtending ports, between network ports and user ports, between the controller port and each ASAM port and between the controller and the network ports and subtending ports. > The drawing in the slide gives you the different possible links and the flooding strategy (Layer2) of the frames. > The handling of control protocol frames (Radius, VBAS, IGMP, ARP and DHCP) and internal communication at a layer higher than the MAC layer is not in the scope of the rules explained hereafter. > Frames received over a network interface: can be (layer 2) forwarded by the Service Hub to the ASAM, the user, the subtending, and the control interfaces. In PPPoE demo, ISM1 related ports are at the same position as network interface. > Frames received over an ASAM interface: can be forwarded to the network interfaces and to the control interface. > Frames received over a subtending interface: can be forwarded to the network interfaces or to the control interface. > Frames received over a user interface: can be forwarded to the network interfaces or to the control interface. > Frames received over the control interface: can be (layer 2) forwarded to the network, the subtending, the user, the ASAM interfaces.
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© 2008 Alcatel Bell N.V., All rights reserved
Upstream Only user to network allowed -->
-->
-->
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> The ISAM only allows user to network communication in the upstream, • Blocked on the same LT by the IWF • Blocked by the port mapping configuration on the SHUB (see later) > This is valid for all cases, i.e. Broadcast (BC), Unknown MAC Destination Address and Known MAC Destination address. > unicast frames with unknown destination MAC addresses are flooded to the networkside. • no user to user communication within the LIM • no flooding from user to user port • broadcast frames are flooded towards the NW port … > frames with known destination MAC addresses aren’t forwarded to user ports, but to the networkside • No user to user communication within the LT
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© 2008 Alcatel Bell N.V., All rights reserved
Downstream Broadcast control configurable per VLAN in IB mode BC --> Network
SHUB
Unknown MAC DA --> Network
SHUB
Known MAC DA --> Network
SHUB
--> --> --> --> -->
--> --> --> --> -->
--> --> --> --> -->
LT
--> -->if BC allowed -->
User A - LT1 User B - LT1 User C - LT4 User D S-ASAM
LT
--> --> -->
User A - LT1 User B - LT1 User C - LT4 User D S-ASAM
LT
--> --> -->
User A - LT1 User B - LT1 User C - LT4 User D S-ASAM
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> Broadcast from Network to User only allowed if enabled by the operator, per VLAN in IB mode. > For the ‘unknown MAC DA case’, the LT will not forward the frames to the users. > In case of a known MAC DA, all frames are forwarded. > unicast frames with known MAC DA are forwarded to the appropriate logical user port • unicast frames with unknown MAC DA are discarded • No flooding from NW port to user port • No user to user communication > By default broadcast as a consequence of flooding, which happens in case of standard bridging when the MAC DA is unknown or in case of multicast, is avoided with intelligent bridging.
TAC03001 _D Ed01
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© 2008 Alcatel Bell N.V., All rights reserved
Duplicate MAC-address learning
port
Mac@
x
Mac A
y
Mac A
ETH
Mac A
?
Port x
Port y
Packet with destination address Mac A
Mac A
Problem: 2 users with same MAC-address, forwarding engine can’t distinguish
Traffic from duplicate MAC-address in separate DSLAM, can be distinguished as separate flows in the Ethernet switches of the aggregation Network, when different VLAN id per DSLAM is used 31
> If a user on line x is using a certain MAC-address and a second user on a different line y is trying to connect with the same MAC-address, a mechanisme should be there so that that MAC-addresses will only appear once in the (filtering db) learning table of that VLAN. > If this would not be done, then the MAC-address would be overwritten in the bridge's learning table, such that traffic is forwarded either to user A or B in a rather unpredictable way. so this feature allows to guarantee uniqueness of MAC-addresses in the aggregation network. > In the 7302 ISAM specific rules are implemented making sure that the MAC-address will only be learned once, this is what they call secure MAC-address learning > We are not only resolving the customer segregation issue but we also avoid that in case of a malicious user, user 1 cannot take over the MAC-address of user 2 (MAC-address antispoofing, blocking duplicate MAC-address) > PS: MAC-addresses are supposed to be unique per VLAN. They are not necessarily unique for the complete system.
TAC03001 _D Ed01
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© 2008 Alcatel Bell N.V., All rights reserved
Secure MAC address learning Service Hub
LT
MAC movement to highest priority
Blocking duplicate MAC-address
Static MAC-addresses never disappear from learning table
Within priority 2 , always MAC Movement
Within priority 3 , MAC movement only when feature is enabled in the VLAN
E-MAN
network links, outband MGT link
2
NT
1 3
Control link
IWF
2
LT
3
subtending links
LT
ASAM links
IWF
3 3
user links
32
> On the IWF If the MAC-address was already configured or learnt on another user logical port, the MACaddress won’t be learnt on the second port and the frame is dropped (Conflict alarm) > On the Service Hub You have the possibility to provision, if MAC movement is allowed or not on a per VLAN basis. The default value is no MAC movement . Mac movement means that in case the same MAC-SA is received on a second interface , the MAC-address will enter the learning table of that interface and is removed from the 1st If you do not perform MAC movement, it means that the duplicate MAC-address is not learnt on the 2nd interface and the frames are discarded > If the Service Hub receives a frame with MAC SA on a different interface than previously learnt, then it will apply the following rules: > Control interface has first priority: Learning a MAC address on the control interface will always take priority on the learning of MAC addresses on a network, an ASAM user or subtending interface, irrespective of the order of learning. > Network interface has second priority: In case the MAC address is first learnt on a subtending, ASAM or user port, and then on an Ethernet network interface, then this movement of the MAC address will be learnt (meaning that the MAC address on the subtending, user or ASAM port is removed). In case the Duplicate MAC-address is learnt on a network interface but it was learnt before on another NW interface the last one takes priority. > ASAM link, subtending link, user link have third priority. If the duplicate MAC address is received on a ASAM, user or subtending port, and the same MAC address is already learnt on an Ethernet network interface in the same VLAN, then the MAC address is not learnt and the frame is dropped. > If the duplicate MAC address is learnt on a DSLAM, user or subtending port, and the same MAC address was already learnt on a port within this priority the action will depend on the configuration of the VLAN. ( MAC movement allowed or not – configurable per VLAN). > Well-known MAC addresses (e.g., MAC addresses allocated for IEEE protocols, ...) will not be learnt. Also the MAC address of the Service Hub is a well known MAC address.
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Secure MAC address learning Configure maximum number MAC-addresses per port Prevents attacks that would fill up the bridging tables Subscription rules: maximum devices connected simultaneously.
Configure MAC-addresses for Discarding Internet
ISP MacC
IP
MacB
Port x
bridged
ETH
BAS
MacA
PADI with source address=MacC
ISAM VLAN ID
Discard Mac@ 00-08-02-E9-F2-9D
port x
Max Mac@ 2
port
Mac@
x
MacA
x
MacB
Connected via PPPoE
33
> There are 2 motivations to block the number of MAC-addresses per port : - Security: avoid that a malicious user can fill up all the complete bridging table of devices in the network (DSLAM and others), by sending traffic with different MAC addresses. - Service differentiation: by limiting the number of MAC addresses per port, the operator can offer different types of service subscriptions to the user, limiting or allowing a certain number of devices to connect simultaneously to the network. For this application, it is clear that the limitation should be configurable per port. > Note: In this example the users PCs are connected to the internet via PPPoE. In that case actually the BAS also has the possibility to limit the number of PPPoE sessions per user-id. Within PPPoE, the unique PPPoE session-id can be used to provide this additional security. The BAS can use the PPPoE session-id for user-identification during the session itself which is linked to an earlier username/password given during the PPPoE session set-up. The BAS knows that user has been given so many sessions. If you have information on VP/VC you can of course also additionaly limit the number of PPPoE sessions per VP/VC. In case of Ethernet Backhaul however the BAS has no info on the VP/VC. Within DHCP there is no information that identifies the user. In that case limiting the number of MAC-addresses learnt per port on the DSLAM is a possible solution, but what with a multiedge environment? . If we want the DHCP server itself to be able to limite the number of sessions of the user, the DHCP request needs to provide the information that defines the user ( VP/VC , port …) This is possible by implementing DHCP-option 82 (see later) > During the creation of a RB-VLAN in the Residentail Bridge VLAN service template, a list of MAC-addresses for discarding can be added.
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© 2008 Alcatel Bell N.V., All rights reserved
Intelligent Bridging, things to consider Security Services ! IP edge has no info on the line id Solutions: PPP-connections (BRAS) or DHCP option 82…
User can access network with a different IP address than the assigned IP address. Pure layer 2 device
No support for duplicate MAC-addresses on the same ISAM Within the same VLAN
Scalability Switches learn all MAC addresses of all end-users IP edge learns all MAC addresses & IP addresses of all end-users
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Anti-IP spoofing: blocking of traffic when user tries to connect to the network with an IP address different than the IP address which was assigned to him.
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© 2008 Alcatel Bell N.V., All rights reserved
Intelligent Bridging, things to consider Advised to use unique VLAN per [IPedge-DSLAM]-pair in EMAN Avoid user-to-user communication Traffic management per DSLAM Complex IP network configuration
When 1 VLAN shared by multiple DSLAMs User to user traffic in EMAN Easy IP network configuration One single subnet for all DSLAMs MAC-address spoofing Standard MAC address learning at EMAN level Traffic will be rerouted to any spoofed MAC address
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© 2008 Alcatel Bell N.V., All rights reserved
University Configuring a RB VLAN
Alcatel-Lucent University Antwerp
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IB VLAN set-up VLAN set-up:
Create VLAN for service to be deployed
Create VLAN Creation of VLAN on SHUB and ASAM-CORE
Add ports to VLAN
Add ports to VLAN
On SHUB and LTs
Via AMS Different versions of one VLAN possible
37
> Here you’ll learn how to: • Distinguish different forwarding models and choose the right VLAN mode for a certain forwarding model • Create a VLAN on Service hub and ASAM-CORE, either using 5520AMS or using CLI • Add ports to a VLAN.
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© 2008 Alcatel Bell N.V., All rights reserved
Creation of IB VLAN Creation of VLAN in 2 steps on SHUB on LTs (ASAM-CORE)
VLAN mode according to forwarding model Create VLAN Mode i.f.o service to be deployed
Create VLAN on ASAM-CORE Residential bridge
Create VLAN on SHUB Residential bridge
38
> The VLAN type in the service hub permits us • to do consistency checks between SHUB and ASAM CORE (with AMS) • to couple specific configuration behavior to a VLAN. > Intelligent (Residential) Bridging mode: forwarding based on L2 and multiple user connections can be associated to each VLAN. • RB on ASAM-CORE: multiple end-user ports can be assigned to a RB VLAN • RB on SHUB: one VLAN on the SHUB that will be associated to all (configured) network ports and ASAM ports – Note: When configuring with CLI, operator needs to make sure that if needed port is added to respective VLAN. Using AMS, it depends if the egress ports on the service hub were forbidden or not. See further. – Note: There’s no difference when you create a VLAN as RB or L2Terminated on the SHUB. There is however a difference on the ASAM-CORE side.
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© 2008 Alcatel Bell N.V., All rights reserved
VLAN modes (except for cross-connect) VLAN mode
SHUB
LTs (ASAM-core)
Intelligent Bridge
Residential bridge
Residential bridge
IP aware Bridge (forwarding)
Layer2 Terminated *
Layer2 Terminated *
Routed
Layer2 Terminated NW port & v-vlan *
Layer2 Terminated *
Model
* : see next chapters
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> Routed mode: Forwarding decision in ASAM-CORE is based on L3 (IP forwarding) . SHUB behaves as a Full router. • L2 terminated on ASAM-CORE: association with V-VLAN based on IP DA. • Layer2-term-nwport on SHUB: a VLAN on the SHUB will only be associated to network ports. That means the VLAN is terminated on the SHUB. > In Cross-connect mode different models exist • C-VLAN cross-connect : Straightforward VLAN cross-connect model where one or more VLANs at the EMAN side are associated with a given PVC at the user side – CC on ASAM-CORE : only one end-user port (PVC or bridge port EFM) associated to a specific C-VLAN – CC on SHUB: since there’s only one user associated to a specific C-VLAN on the SHUB one ASAM-link and one or more network ports are associated to the VLAN • S-VLAN at the EMAN side is associated with a PVC at the user side, the C-VLANs carried within the S-VLAN are then passed transparently to the end user. – CC on ASAM-CORE : only one end-user port (PVC or bridge port EFM) associated to a specific S-VLAN – CC on SHUB: since there’s only one user associated to a specific S-VLAN on the SHUB one ASAM-link and one or more network ports are associated to the S-VLAN • S-VLAN/C-VLAN cross-connect mode : PVC – C-VLAN mapping, where the S-VLAN tag can be used by the EMAN as route-identifier towards the ISAM – CC on ASAM-CORE : Different end-user ports (PVC or bridge port EFM) can be associated to a specific S-VLAN. The C-VLAN identifies the user-port – CC on SHUB: since there’s can be many users associated to a specific S-VLAN on the SHUB all ASAM-link and one or more network ports are associated to the VLAN.
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© 2008 Alcatel Bell N.V., All rights reserved
Creation of IB VLAN on NE
equipment
S-VLAN Id = 0 Select NE Infrastructure Layer 2 VLAN
see next slide
Create VLAN Create SHUB VLAN
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> 5520AMS doesn’t use templates for VLANs. The only way to configure VLANs is on the NE itself. > For a residential bridge VLAN, the S-TAG = 0. No stacked VLANs for intelligent bridging! (The reason why you see the S-VLAN id is that the same screens are used for cross-connect, where you can have stacked VLANs indeed.)
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© 2008 Alcatel Bell N.V., All rights reserved
Creation of IB VLAN on NE
mode: RB
protocol filter (PPPoE / IPoE) broadcast control PPPoE relay tag
DHCP option 82
Virtual MAC translation 42
> Not all parameters can be configured here already. You can configure e.g. static MAC addresses afterwards. See further. > From R3.5 VLAN specific aging time can be set. If set, this value will override the IACM Layer2 - Ethernet System Parameters – Forwarding Database Aging Time. If on the other hand the default value –1 is left, the IACM system parameter is used.
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© 2008 Alcatel Bell N.V., All rights reserved
Modifying IB VLAN on NE equipment
Static MAC addresses
Select NE Infrastructure Layer 2 VLAN Select VLAN MAC Addresses Static Create Static MAC Address 43
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Creation of IB SHUB VLAN
equipment
Select NE Infrastructure Layer 2 VLAN
see next slide
Create VLAN Create SHUB VLAN
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> For all SHUB VLANs, only one VLAN tag is relevant.
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Creation of SHUB VLAN Define egress ports on SHUB
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> Tag mode can be configured on network ports – Configure vlan shub id untag-port network: – ASAM-links support only tagged frames
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© 2008 Alcatel Bell N.V., All rights reserved
Modifying SHUB VLAN
Object details MAC movement IGMP settings … 46
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Residential bridge parameters BC button not checked by Default
Broadcast control on LT Only applicable in IB mode
MAC-DA Broadcast
Disabled (default):
From Service Hub
LT
– BC in IWF on LT blocked in DS Enabled: – Allow BC in DS
NT
MAC movement on SHUB
SHUB
Only applicable in IB mode
E-MAN
Disabled (default): – No MAC movement in SHUB within priority 3 interfaces Enabled: – MAC movement allowed within priority 3 interfaces
2 2
1 LT
3 LT
3 3 3
47
> Disabled:
Button not checked
> Enabled:
Button checked
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© 2008 Alcatel Bell N.V., All rights reserved
Residential bridge parameters DHCP option 82/PPPoE Relay Tag Disabled (default): No option 82/PPPoE information added by LT
Enabled: Option 82/PPPoE information added by LT
Protocol Group Filter Different from Protocol based VLAN association 3 possibilities All : IPoE: PPPoE : PPPoE + IPoE:
allow all protocols on VLAN allow only IPoE on VLAN allow only PPPoE on VLAN allow only PPPoE and IPoE on VLAN
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> Protocol based VLAN association
TAC03001 _D Ed01
see later
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© 2008 Alcatel Bell N.V., All rights reserved
Creation of IB VLAN via CLI Vlan ID range: 1 to 4093 Exluding the VLAN ID used for management
Create VLAN on ASAM-CORE configure vlan id < VLAN ID> mode
Create VLAN on SHUB configure vlan shub id mode egress-port network: egress-port lt:rack/shelf/slot
49
CONFIGURATION OF VLAN ON ASAM-CORE > Id: [2...4093,4097] vlan id
Same for VLAN on SHUB
> Name: optional parameter with default value: "“ name > Mode: Mandatory parameter with possible values (on ASAM-CORE): 1) cross-connect, 2) residential-bridge, 3) qos-aware, 4) layer2-terminated > Priority: optional parameter with default value: 0. Range: {0...7} > [no]switch-broadcast: optional parameter to control downstream broadcast frames (default value:"discard-broadcast“). Broadcast control is configurable per VLAN: on/off • [No] broadcast frames
‘broadcast frames’ means: broadcast allowed (= ON)
> [no] protocol filter (default: pass all). Other possibilities: pass pppoe ,pass ipoe,pass pppoe-ipoe > [no]enable-pppoe-relay: optional parameter with default value: "disable-pppoe-relay“ adding tag for pppoe relayed traffic (rb vlan) > [no]dhcp-opt-82-on: optional parameter with default value: "dhcp-opt-82-off“ enable adding dhcp option 82 (rb vlan) CONFIGURATION OF VLAN ON SHUB > Mode: Mandatory parameter with possible values (on SHUB): 1) cross-connect, 2) residential-bridge, 3) layer2-terminated, 4) layer2-term-nwport, 5) v-vlan = virtual vlan, 6) reserved (internal and external communication via vlan) > [no] mac-move-allow: for residential bridges (no) mac-address movement allowed between priority 3 ports (ASAM ports, subtending ports and user ports on the SHUB). > Note: Adding ports to the VLAN also with “configure VLAN” command, but not in one go with the creation of the VLAN! You need to enter two consecutive commands. (see next chapter – add port to VLAN)
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Add port to a IB VLAN on the SHUB via CLI (2/2) Attachment of ports to the VLAN on SHUB for IB. Define egress ports in the “configure VLAN shub” command Configure>vlan>shub>id egress-port lt: defines an ASAM-link Configure>vlan>shub>id egress-port network: defines an external NT port
Tag mode can be configured on network ports Configure vlan shub id untag-port network: ASAM-links support only tagged frames
50
> Attachment of ports to the VLAN included in the
“configure VLAN SHUB” command.
• configure vlan shub id mode residential-bridge • Optional parameters – [no] name – [no] mac-move-allow – [no] egress-port – [no] untag port
> [no] name: VLAN name (default none) > [no] mac-move-allow: allow mac-address movement between ports with priority 3 (user ports, ASAM ports, subtending ports). Default: no mac-address movement allowed. > [no] egress-port: ports to be added to the VLAN. Three different types of egress-ports exist: • LT (ASAM port) • Network • NT (any port on the NT, e.g. a user port or subtending port) > [no] untag port: send frames (un)tagged on egress-port.
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© 2008 Alcatel Bell N.V., All rights reserved
University IB VLAN association on bridge port
Alcatel-Lucent University Antwerp
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Definition of logical user port on ASAM-CORE x/Eth
x/Eth
x/ATM/ADSL
xDSL based on ATM LT 1
IWF FW Engine
1 VP/VC is mapped on 1 logical user port on IWF of LT. xDSL line can have multiple VP/VCs
PVC / Logical user port CPE
xDSL based on Ethernet (VDSL2/EFM)
IWF EFM / Logical user port
FW Engine
1 end user is mapped to one logical user port on the IWF of the LT
LT 1
One to one mapping subscriber VLANs can be defined
CPE
x/Eth
X/Eth/Phys layer
x/Eth
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> xDSL based on ATM • 1 VP/VC used per service (HSI, VoIP, STB), max 8 VP/VC per xDSL line > xDSL based on Ethernet • VLAN per Service on UNI for all services, VLAN translation • CPE generates the VLAN in function of the (ISP, Service), potentially requiring CPE management in case of wholesaling • QoS discrimination per VLAN (priority remarking, policing, …) • Multicast replication (one VLAN only) • Option 82 and PPP relay in ISAM (ideally with VLAN Id in option 82 or PPPoE relay tag)
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IB VLAN association of port on ASAM-CORE One logical user port can be mapped to multiple VIDs One logical port associated to CC or Residential-bridge VIDs One logical user port can accept tagged or untagged frames Configured on the level of VID Association
Per user logical port a PVID can be defined Before PVID can be configured VLAN association has to be configured Configuration of VID within the bridged port
Support of 48 x 16 = 768 I-Bridges on L3 LIMs
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IB VLAN association Port based VLAN association VLAN ID based on port of arrival Untagged frames, receive port VLAN identifier – PVID Also called the default VLAN ID
Port-and-protocol-based VLAN classification VID based on port of arrival and the protocol identifier of the frame Multiple VLAN-ID’s associated with port of the bridge – VID set
VLAN Translation VID based on port of arrival and translated to a network VID
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> A VLAN bridge supports port-based VLAN classification, and may, in addition, support portand-protocol-based VLAN classification > In port-based VLAN classification within a bridge, the VLAN-ID associated with an untagged or priority tagged frame is determined based on the port of arrival of the frame into the bridge. This classification mechanism requires the association of a specific Port VLAN Identifier, or PVID, with each of the bridge’s ports. In this case, the PVID for a given port provides the VLAN-ID for untagged and priority tagged frames received through that port. > For bridges that implement port-and-protocol-based VLAN classification, the VLAN-ID associated with an untagged or priority-tagged frame is determined based on the port of arrival of the frame into the bridge and on the protocol identifier of the frame. For port-and-protocol based tagging, the VLAN bridge will have to look at the Ethertype, the SSAP, or the SNAP-type of the incoming frames. When the protocol is identified, the VID associated with the protocol group to which the protocol belongs will be assigned to the frame. This classification mechanism requires the association of multiple VLAN-IDs with each of the ports of the bridge; this is known as the “VID Set” for that port. > BTV and Port & protocol-based VLAN on R3.1-3.2 • the port default VLAN must be chosen equal to the VLAN used for BTV traffic • no protocol based VLAN must be defined for IP, otherwise we end up generating a wrong tag when issuing IGMP messages to the end user
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IB VLAN association of port on ASAM-CORE Frames received from end users are untagged User port can be mapped to multiple VID using portProtocol based association or PVID
Frames received from end users are tagged On logical port define different VIDs and configure frames received from end-user as tagged Send frames back to the subscriber to be set as Single Tagged
E-MAN Network
IPoE PPPoE xxx
LT
IPoE PPPoE xxx
CPE
E-MAN Network
LT
CPE
= PVID
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Behavior of the RB VLAN Association on the AMS > Frames received by the end users are tagged • Association Settings
Send frames back to the subscriber as: Single Tagged
> Frames received from end users are untagged • Association Settings
TAC03001 _D Ed01
Send frames back to the subscriber as: Untagged
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© 2008 Alcatel Bell N.V., All rights reserved
IB VLAN association of port on ASAM-CORE VLAN Translation, frames received from end users are tagged Bridge Port
Network VLAN VLAN 10 (HSIA, SP1) VLAN 11 (HSIA, SP2) VLAN 20 (VoD, SP1)
Subscriber VLAN
Bridge 10
VLAN 1 (HSIA)
Bridge 11
VLAN 5 (HSIA)
Bridge 20
VLAN 2 (Video)
VLAN 30 (BTV, SP1) VLAN 31 (BTV, SP2) VLAN 21 (VoD, SP2) VLAN 40 (Voice, SP3)
MCast
CPE
Bridge 21
VLAN 6 (Video)
Bridge 40
VLAN 3 (Voice)
VLAN per service & per provider
VLAN per service & per provider
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> There are many operators who base their network architecture on one PVC per service when connecting ADSL subscribers. Once those operators start deploying VDSL, they need to use the VLAN as a "PVC emulation". > The ISAM support the ability to emulate a multi-PVC configuration on an EFM interface using the VLAN as a "PVC emulation", i.e. it is possible to associate a set of VLAN Id's at the subscriber interface with a set of forwarding engines being chosen from the following list : • VLAN-CC (Transparent or Protocol aware) In this case, the C-VLAN received at the user side is either forwarded as a C-VLAN CC or encapsulated into an S-VLAN (VLAN stacking). • i-Bridge In this case, the VLAN received at the user side will be bridged into an i-bridge identified by the same VLAN Id. • IP Aware Bridge • IP Routing > Additionally, in case of VLAN-CC or i-Bridge, we support VLAN translation to make wholesaling possible without impacting the CPE configuration : starting from a set of predefined C-VLAN tags at the CPE side (i.e. the same for all CPEs), it is possible to retag the received packet with a new C-VLAN (VLAN-CC or i-bridge) or a stacked VLAN (VLAN-CC), so that the traffic can be passed to the VLAN associated with the couple (serivce provider, service).
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© 2008 Alcatel Bell N.V., All rights reserved
Configuration of the port on VLAN in IB Add ports to VLAN
on SHUB Define egress ports within the VLAN
on ASAM-CORE Bridge port – VID mapping
External ethernet links
Control link
Aggregation FE function
Control/mgt functions
GE/FE 1 GE/FE 2 ….. GE/FE 7 GE1 …..
ASAM links
LIM IWF
LIM IWF
GE16
PVC PVC
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• In the SHUB – Create VLAN in RB mode – Add NW interfaces and all ASAM interfaces to this VLAN • In the ASAM – Create VLAN in RB mode – Add port to VLAN
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Create VLAN association on bridge port (1/2)
equipment
Select configured bridge port Create VLAN Association
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Create VLAN association on bridge port (2/2)
define scope (local for subscriber VLAN
send frames back to subscriber as: untagged 59
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Define PVID on bridge port Modify VLAN association
Object details view
select default VLAN and click OK 60
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RB VLAN association with VLAN translation VLAN scope: local equipment
local subscriber VLAN
Select configured bridge port
select network VLAN
Create VLAN Association
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> E.g. you configure a RB VLAN association with VLAN translation on a VDSL EFM bridge port. The modem is configured in such a way that it generates tagged traffic, e.g. local subscriber VLAN 10. This subscriber VLAN is translated into the network VLAN 150. • All frames returned to the subscriber should again have VLAN tag 10. Configure that the frames returned to the subscriber should be single-tagged.
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IB VLAN association of port on ASAM-CORE (CLI) define VIDs in the “configure bridge port” command configure bridge port 1/1//::# vlan-id or vlan-id stacked
VLAN Translation Configure bridge port 1/1//::# vlan-id vlan-scope network-vlan
Define PVIDs in the “configure bridge port” command configure bridge port 1/1//::# pvid
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> No VLAN Translation: • leg:isadmin>configure>bridge>port>1/1/4/1:8:36# vlan-id 720 • leg:isadmin>configure>bridge>port>1/1/4/1:8:36# info • #--------------------------------------------------------------------------------------------------• port 1/1/4/1:8:36 max-unicast-mac 4 vlan-id 720 exit • Exit > With VLAN Translation: • leg:isadmin>configure>bridge>port>1/1/4/1:8:36# vlan-id 100 vlan-scope local networkvlan 720 • leg:isadmin>configure>bridge>port>1/1/4/1:8:36# info • #--------------------------------------------------------------------------------------------------• port 1/1/4/1:8:36 max-unicast-mac 4 vlan-id 100 network-vlan 720 vlan-scope local exit • Exit
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Deletion of VLAN First remove VLAN associations on VLAN
Then delete VLAN
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Deletion of VLAN It is not possible to delete a VLAN if there are still ports attached to the VLAN Deleting VLAN on ASAM-CORE configure vlan no id
Deleting VLAN on SHUB configure vlan shub no id
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VLAN related show commands Selection of multiple show vlan commands Display list of command via “Show vlan ?” Interesting commands on ASAM-CORE Show vlan residential bridge gives al bridge ports connected to vlan Show vlan bridge-port-fdb < bridge port id > Gives all MAC-adresses learned or configured on that port Show vlan fdb Gives you MAC -adresses learned on all ports of that vlan Show vlan port-vlan-map Gives all the VLANS to which that port is mapped
Same commands available on shub
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University Exercises
Alcatel-Lucent University Antwerp
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> Perform these exercises with CLI and AMS unless specified differently
Perform these exercises on the board and ports assigned to you to do the retrieval exercises.
1. Which VLANs are created on the NE?
2. What is the forwarding mode of VLAN 200 (cross-connect, residential bridge)?
3. What are the ports belonging to VLAN 200 on the SHUB? Explain what you see.
4.
Which logical ports are associated to VLAN 200?
5. Explain the total configuration of the user logical port PVC 8/35 on port TRAINING-a . Note : For the downstream forwarding , we assume that the SHUB knows the MAC-addresses of the end user within the respective VLANs .
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> What happens when the end-user sends a frame with VLAN tag 200?
> What happens when the end-user sends a frame with VLAN tag 300?
> What happens when the end-user sends an untagged frame ?
> What happens with a frame with VLAN tag 200 coming from the network?
> What happens with a frame with VLAN tag 300 coming from the network?
6. How many MAC-addresses can be learnt in VLAN 200 on the logical user port VP/VC 8/35 of port TRAINING-a?
7. Explain the total configuration of the user logical port PVC 8/35 on port TRAINING-b. Note : For the downstream forwarding , we assume that the SHUB knows the MACaddresses of the end user within the respective VLANs . Egress
Ingress
DSL port
DSL port 150
150
160
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8/35
160
210
210
50
50
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What happens when the end-user sends a frame with VLAN tag 150?
What happens when the end-user sends a frame with VLAN tag 50?
What happens when the end-user sends an untagged frame?
What happens when a frame with VLAN tag 150 is sent towards the end user?
What happens when a frame with VLAN tag 160 is sent towards the end user?
What happens when a frame with VLAN tag 210 is sent towards the end user?
What happens when a frame with VLAN tag 50 is sent towards the end user?
What happens when an untagged frame is sent towards the end user?
8. How many MAC-addresses can be learnt on the user logical port PVC 8/35 on port TRAINING-b within VLAN 50?
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For these exercises go back to the board and ports assigned to you to do the configuration exercises. 1. Go to the port that you configured before and where the modem is connected. Use CLI to apply the service with VLAN id as default VLAN 150 to PVC 8/36. Frames coming from the end user are untagged. You should be able to connect with 2 PCs. DHCP server is available on the other side . setup
2. Check if you are able to get an IP address. from the DHCP server. Note: in function of the modem setup you need to either use VMware on the trainee PC or disconnect your PC from the AUA – LAN and connect the PC to the modem (or connect your own PC to the modem … ). Ask the teacher what to do! Force your PC to ask for a new IP-address (DHCP release/renew) ipconfig /release and ipconfig /renew. What is the IP-address you received ? What is the IP-address of the DHCP server?
3. Check the MAC-address learnt on your bridge port using AMS and CLI.
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4. Are you able to ping the PC of one of your colleagues connected to the same ISAM? Explain.
5. Use the AMS to associate logical port 8/35 with VLAN 200 as the default VLAN. Frames coming from the end user are untagged. You should be able to connect with 3 PCs to this connection. VLAN 200 terminates on a BRAS so use PPPoE to set up a connection. Check if you can surf the web. Note: in function of the modem setup PPPoE session needs to be initiated from modem or PC . Ask the trainer what to do ! Setup
6. Check the MAC-address learnt on the VP/VC 8/35 and VP/VC 8/36 with the AMS. What do you notice ? Explain what you see. 7. Use the AMS to remove the RB vlan with id 200 from the 8/35 ATM termination point on your port.
8. Use the CLI to remove the RB vlan with id 150 from the 8/36 ATM termination point on your port.
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9. Create RB VLAN with VLAN ID=20x ( x = adsl-x) via CLI. All traffic type is possible within the VLAN. The VLAN is default VLAN on logical port 8/35. 4 user sessions possible on the logical port. No user line id is required for DHCP or BRAS. No MC service is deployed within the VLAN. Try to initiate a PPPoE session towards the network. Verify if your configuration works. Note: BRAS will not provide you with an IP@ ( Setup of the network currently not ready ) Setup
10. Create a Service for RB VLAN on the AMS. All traffic type is possible within the VLAN. 4 user sessions possible on the logical port. No user line id is required for DHCP or BRAS. No MC service is deployed within the VLAN. Leave status under construction. Note : unique VLAN-ID per [IP-edge – ISAM] pair to prohibit user-to-user communication.
11. You want to have line identification information on the DHCP server. Try to apply the change and explain
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12. Use the AMS to associate the service you just created on VP/VC 8/36 of the port assigned to you. VLAN id to be used is VLAN 16x (x=adslx). Frames coming from the end user are untagged. VLAN 16x is the default VLAN. Check if your configuration works by setting up a DHCP session and see if you are able to receive an IP@ . Setup
13. Release your IP address. (ipconfig /release)
14. Your management changed mind and the VLAN 16x can only be used for PPPoE traffic. Apply the change with CLI. Check if you are still able to retrieve an IP@ via DHCP. Does it work ? Why? Why not?
15. In normal operation would you normally apply such change with CLI?
16. Your management changed mind again, and now only wants IPoE traffic in VLAN 16x and disable option 82. Apply the change with AMS. Check if you are still able to retrieve an IP@ via DHCP. Does it work ? Why? Why not??
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17. Can you ping the client PC from the server side on VLAN 16x? Ask the trainer to assist you since access to DHCP server is secured. First check the ARP table of DHCP server and make sure the MAC@ of your PC is no longer in the self-learning table of VLAN 16x, then issue the ping command. What do you notice? Explain.
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Force the system to allow broadcast frames to pass through in the downstream direction. Use a CLI command to achieve this goal. Verify, and explain what you notice.
19. Delete the association with VLAN 20x from VP/VC 8/35 on your port and associate VP/VC 8/35 with VLAN 21x. VLAN 21x is a RB service and parameters are such that only PPPoE traffic is allowed on this VLAN. Perform this exercise with the AMS. Check if your setup works . What is the IP@ you get from the BRAS ? What is the IP@ you got from the DHCP server? Note: BRAS will not provide you with an IP@ ( Setup of the network currently not ready ) Setup
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20.
Try to delete VLAN 16x from the ISAM via the AMS. What happens? Explain. Note: If not possible just proceed to the next exercise after explanation
21.
Version 2 of service with VLAN-ID 16x has been deployed in the entire network. Delete version 1 from the AMS.
22.
MC Teaser . Set-up a MC control-channel on VP/VC 8/36 and allow your user to see package 1 . Ask the teacher for assistance and see if you can watch some video.
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