10 - IP Telephony Services

IP Telephony Services

4-1 Copyright © 2005 Juniper Networks, Inc.

Proprietary and Confidential

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Power over Ethernet  PoE is defined in IEEE 802.3af and facilitates the delivery of regulated power over a standard copper Ethernet network cable  PoE deployments consist of two primary components: •PSE provides power

•PD accepts and utilizes delivered power

© 2008 Juniper Networks, Inc. All rights reserved.

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Power Classification  IEEE 802.3af has an optional power classification feature that allows a PSE to budget the required power based on the class of the attached devices, significantly reducing power capacity requirements •With power classification: The switch (PSE) identifies power needs and reserves power for PDs based on class •Without power classification: The switch (PSE) assigns all PDs the default class (Class 0), which budgets a full 15.4 watts per port

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Power Class Definitions Class Number

Maximum Power at Output Port of PSE

0 (Default)

15.4 watts reserved (Actual device requirement can be less)

© 2008 Juniper Networks, Inc. All rights reserved.

1

4 watts

2

7 watts

3

15.4 watts

4

Future expansion

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Power Management  Power management modes include: •Static: Power is deducted from the total power pool as specified by the user for that interface • Ensures that the maximum power specified for the interface is always reserved

•Dynamic: Power budgeted from the total power pool for each port matches the actual power consumed •Class: Power budgeted from the total power pool for each port matches the maximum power for the power class

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Power Pool Usage Guidelines  Three power supply capacities:

Power Supply Switch Power Budget Consumption for PoE Pool Capacity

•320 W, 600 W, and 930 W

 Any power supply can be installed in any switch model  Installing a higher capacity power supply does not increase the number of PoE ports on the switch

© 2008 Juniper Networks, Inc. All rights reserved.

320 W

600 W

930 W

190 W

130 W (8 PoE ports at 15.4 W each)

190 W

410 W (24 PoE ports at 15.4 W each)

190 W

740 W (48 PoE ports at 15.4 W each)

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PoE Telemetries  Switch provides telemetries support to keep history of power usage for each PD •Disabled by default; you enable PoE telemetries through configuration and specify duration and interval values

[edit poe interface interface-name telemetries] user@switch# set ? Possible completions: + apply-groups Groups from which to inherit configuration data + apply-groups-except Don't inherit configuration data from these groups disable Disable telemetries duration Duration to continue recording of data (1...24 hours) interval Interval at which data should be recorded (1...30 minutes)

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Configuring PoE [edit poe] user@switch# show interface all | interface { disable; priority high | low; maximum-power watts; telemetries { disable; interval minutes; duration hours; } }

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Determines priority for shutdown of individual ports when there is insufficient power for all PoE ports Sets maximum amount of power that can be supplied for a port

Allows per-port PoE consumption tracking

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Monitoring PoE (1 of 2)  Use the show chassis hardware command to verify PoE capabilities user@switch> show chassis Hardware inventory: Item Version Chassis REV X3 FPC 0 REV 02A … Power Supply 0 REV 01 …

hardware Part number 750-021256 711-021264

Serial number BM0207431960 AK0207431816

Description EX4200-24T EX4200-24T, 8 POE

740-020957

AT0507420091

PS 320W AC

•Use the show poe controller command to view PoE power usage and availability user@switch> show poe controller Controller Index 0

Maximum Power 115 W

© 2008 Juniper Networks, Inc. All rights reserved.

Power Consumption 0W

Guard-band 15W

Management Static

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Monitoring PoE (2 of 2)  Use the show poe interface command to verify the operational status of a PoE interface, as well as the actual power being consumed by PDs user@switch> show poe interface Interface Admin-status Oper-status ge-0/0/1 Enabled ON ge-0/0/3 Enabled OFF ge-0/0/5 Enabled OFF …

max-power 15.4W 12.0W 15.4W

priority Low High Low

power-consumption Class 3.5W 0 0.0W 0 0.0W 0

•Optionally, verify the same details for an individual interface user@switch> show poe interface ge-0/0/3 PoE interface status: PoE interface : ge-0/0/3 Administrative status : Enabled Operational status : OFF Power limit on the interface : 15.4W Priority : High Power consumed : 0.0W Class of power device : 0

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Voice VLAN  The voice VLAN feature enables access ports to accept both untagged (data) and tagged (voice) traffic and separate that traffic into different VLANs

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Usage Guidelines  When using the voice VLAN feature: •Recommend to configure CoS before enabling voice VLAN •Enable voice VLAN for switch access ports with IP phones •Use LLDP-MED to provide voice VLAN ID and 802.1p values to attached IP phones

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Configuring a Voice VLAN

[edit ethernet-switching-options] Associates VoIP parameters user@switch# show with all access ports voip { Associates VoIP parameters interface (access-ports | interface-name) { with specified access port vlan (vlan-name | vid); forwarding-class class; } }

Referenced VLAN and forwarding class must be defined locally on switch

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Monitoring Voice VLAN  Use the show vlans detail vlan-name command to verify voice VLAN membership, tag, and state information user@switch> show vlans detail voice VLAN: voice, 802.1Q Tag: 500, Admin state: Enabled Description: Used for Voice Traffic Number of interfaces: 3 (Active = 3) Tagged interfaces: ge-0/0/0.0*, ge-0/0/1.0*, ge-0/0/10.0*

* = Active

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Link Layer Discovery Protocol  LLDP, as defined in IEEE 802.1ab, is a Layer 2 neighbor discovery protocol that allows network devices to advertise their identity and capabilities  LLDP-enabled devices are called LLDP agents •LLDP agents exchange LLDPDUs •Information learned from neighbors is stored in a database • Database entries are refreshed periodically

 LLDP frames use TLV tuples •LLDP defines a set of mandatory and optional TLVs •LLDP frames are constrained to the local link

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LLDPDU Frame Format

LLDP multicast address: 01-80-C2-00-00-0E

Chassis ID TLV

Port ID TLV

Time to Live TLV

M

M

M

Optional TLV

…

Optional TLV

End of LLDPDU TLV M

M = Mandatory TLV—required for all LLDPDUs © 2008 Juniper Networks, Inc. All rights reserved.

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LLDP Updates  LLDP update considerations: •Periodic updates are sent at regular intervals • Default is 30 seconds; valid range is 5 to 32768 seconds

•Triggered updates are sent when local value changes • Triggered updates conform to 1 per second limit

•Updates are sent as unsecure, one-way advertisements • LLDP is stateless and offers no authentication

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LLDP Transmit Agent  Transmit agent sends periodic and triggered updates •TTL TLV (txTTL) mechanism determines the length of time information remains valid on the receiver: • msgTxInterval (default of 30 seconds) x msgTxHold (default of 4 seconds) • By default, messages are sent with a default TTL value of 120 sec • If information is not refreshed before TTL expires, it is discarded

 Transmit agent notifies neighbor of state changes •Final shutdown LLDPDU is sent with chassis ID, port ID, TTL TLV field set to 0, and end-of-LLDPDU TLV set •If the transmit agent fails to send shutdown TLV before the interface goes down, LLDP is maintained until TTL age timer expires Chassis ID TLV M © 2008 Juniper Networks, Inc. All rights reserved.

Port ID TLV M

Time to Live TLV M

Optional TLV

…

Optional TLV

End of LLDPDU TLV M 18

LLDP Receiver Agent  Receiver stores information in a neighbor database •Neighbor database information is accessible by SNMP •Database is updated to ensure data accuracy

 Receiver maintains statistic counters for each interface; these statistics include: •Frames received •Frames with errors •Unknown TLVs

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What Is LLDP-MED?  LLDP-MED is an extension to LLDP developed by TIA (ANSI/TIA-1057) to support interoperability and enhance discovery between VoIP endpoint devices and other networking devices  LLDP-MED devices are categorized into three classes: •Class 1: All devices requiring base LLDP discovery service •Class 2: Any device with IP media capabilities • Examples include voice and media gateways, and conference bridges

•Class 3: Any device used for end-user IP communications • Examples include IP phones and PC-based softphones

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LLDP-MED Usage  LLDP-MED can be used for the following: •Network policy discovery • Allows a switch to deliver VLAN and CoS settings to an IP phone

•Power negotiation • Allows a switch and IP phone to negotiate power requirements and offerings

•Inventory management • Allows a management system to retrieve system information from endpoint devices

•Location discovery • Identifies the location of IP phones based on the switch port; primary usage is for emergency services

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LLDP and LLDP-MED Interaction  LLDP and LLDP-MED interaction details: •All mandatory LLDP TLVs are advertised in LLDPDUs as soon as LLDP is enabled •All optional LLDP and LLDP-MED TLVs are enabled by default •LLDP-MED TLVs are sent only after detecting a MED device

2. LLDP-MED frame sent by neighbor

3. Agent toggles to LLDP-MED

1. Interface starts advertising base LLDP TLVs (non-LLDP-MED) © 2008 Juniper Networks, Inc. All rights reserved.

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LLDP-MED and 802.1X  LLDP-MED and 802.1X considerations: •When 802.1X is enabled, LLDP frames are not transmitted or received until the port is authenticated •An IP phone and PC connected to the same switch port can be authenticated separately (multiple supplicant mode) and can receive different VLAN assignments and policies for data and voice • If only the IP phone or the PC is 802.1X capable, use the single supplicant mode

© 2008 Juniper Networks, Inc. All rights reserved.

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LLDP and LLDP-MED Example (1 of 4)

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LLDP and LLDP-MED Example (2 of 4)

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LLDP and LLDP-MED Example (3 of 4) Port

Device

Information

ge-0/0/0

Gateway

xxxx

ge-0/0/1

IP phone

xxxx

ge-0/0/2

PC

xxxx

ge-0/0/3

Switch

xxxx

…

…

…

© 2008 Juniper Networks, Inc. All rights reserved.

Port

Device

Information

ge-0/0/0

Switch

xxxx

ge-0/0/1

IP phone

xxxx

ge-0/0/2

PC/Server

xxxx

ge-0/0/3

PC/Server

xxxx

…

…

…

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LLDP and LLDP-MED Example (4 of 4) Port

Device

Information

ge-0/0/0

Gateway

xxxx

ge-0/0/1

IP phone

xxxx

ge-0/0/2

PC

xxxx

ge-0/0/3

Switch

xxxx

…

…

…

SNMP Management Application

SNMP

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Port

Device

Information

ge-0/0/0

Switch

xxxx

ge-0/0/1

IP phone

xxxx

ge-0/0/2

PC/Server

xxxx

ge-0/0/3

PC/Server

xxxx

…

…

…

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Configuring LLDP and LLDP-MED [edit protocols] user@switch# show lldp { disable; advertisement-interval seconds; hold-multiplier number; interface [all | interface-name] { disable; } } lldp-med { disable; interface (all | interface-name){ disable; } } }

© 2008 Juniper Networks, Inc. All rights reserved.

Determines TTL value sent to neighbor devices

Disables protocol on referenced interface (suggested on untrusted boundaries)

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Monitoring LLDP and LLDP-MED  Use the following key commands to monitor LLDP: •Verify LLDP status: user@switch> show lldp detail

•View learned neighbor information: user@switch> show lldp neighbors

•Check local LLDP details: user@switch> show lldp local-info

•View LLDP statistics and counters: user@switch> show lldp statistics

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