10 - ip telephony services
DESCRIPTION
Telefonia Ip - jUNOSTRANSCRIPT
Copyright © 2005 Juniper Networks, Inc. Proprietary and Confidential www.juniper.net
4-1
IP Telephony Services
© 2008 Juniper Networks, Inc. All rights reserved. 2
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. 3
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
© 2008 Juniper Networks, Inc. All rights reserved. 4
Power Class Definitions
7 watts2
15.4 watts3
4 watts1
Future expansion4
15.4 watts reserved(Actual device requirement can be less)0 (Default)
Maximum Power at Output Port of PSE
Class Number
© 2008 Juniper Networks, Inc. All rights reserved. 5
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
© 2008 Juniper Networks, Inc. All rights reserved. 6
Power Pool Usage Guidelines
Three power supply capacities:•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
410 W(24 PoE ports
at 15.4 W each)
190 W600 W
740 W(48 PoE ports
at 15.4 W each)
190 W930 W
130 W(8 PoE ports
at 15.4 W each)
190 W320 W
Power Budget for PoE Pool
Switch Consumpt
ion
Power Supply
Capacity
© 2008 Juniper Networks, Inc. All rights reserved. 7
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)
© 2008 Juniper Networks, Inc. All rights reserved. 8
Configuring PoE
[edit poe]user@switch# show interface all | interface {
disable;priority high | low;maximum-power watts;telemetries {
disable;interval minutes;duration hours;
}}
Determines priority for shutdown of individual ports when there is insufficient power for all PoE ports
Allows per-port PoE consumption tracking
Sets maximum amount of power that can be supplied for a port
© 2008 Juniper Networks, Inc. All rights reserved. 9
user@switch> show chassis hardware Hardware inventory:Item Version Part number Serial number DescriptionChassis REV X3 750-021256 BM0207431960 EX4200-24TFPC 0 REV 02A 711-021264 AK0207431816 EX4200-24T, 8 POE…Power Supply 0 REV 01 740-020957 AT0507420091 PS 320W AC…
Use the show chassis hardware command to verify PoE capabilities
•Use the show poe controller command to view PoE power usage and availability
Monitoring PoE (1 of 2)
user@switch> show poe controller
Controller Maximum Power Guard-band ManagementIndex Power Consumption 0 115 W 0W 15W Static
© 2008 Juniper Networks, Inc. All rights reserved. 10
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
•Optionally, verify the same details for an individual interface
user@switch> show poe interface Interface Admin-status Oper-status max-power priority power-consumption Class ge-0/0/1 Enabled ON 15.4W Low 3.5W 0 ge-0/0/3 Enabled OFF 12.0W High 0.0W 0 ge-0/0/5 Enabled OFF 15.4W Low 0.0W 0…
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
© 2008 Juniper Networks, Inc. All rights reserved. 11
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
© 2008 Juniper Networks, Inc. All rights reserved. 12
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
© 2008 Juniper Networks, Inc. All rights reserved. 13
Configuring a Voice VLAN
[edit ethernet-switching-options]user@switch# showvoip { interface (access-ports | interface-name) { vlan (vlan-name | vid); forwarding-class class; }}
Associates VoIP parameters with all access ports
Associates VoIP parameters with specified access port
Referenced VLAN and forwarding class must be defined locally on switch
© 2008 Juniper Networks, Inc. All rights reserved. 14
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: EnabledDescription: Used for Voice TrafficNumber of interfaces: 3 (Active = 3) Tagged interfaces: ge-0/0/0.0*, ge-0/0/1.0*, ge-0/0/10.0*
* = Active
© 2008 Juniper Networks, Inc. All rights reserved. 15
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
© 2008 Juniper Networks, Inc. All rights reserved. 16
LLDPDU Frame Format
LLDP multicast address: 01-80-C2-00-00-0E
Chassis IDTLV
M
Port IDTLV
M
Time to LiveTLV
M
OptionalTLV
OptionalTLV
End of LLDPDU TLV
M
…
M = Mandatory TLV—required for all LLDPDUs
© 2008 Juniper Networks, Inc. All rights reserved. 17
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
© 2008 Juniper Networks, Inc. All rights reserved. 18
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 IDTLVM
Port IDTLVM
Time to LiveTLVM
OptionalTLV
OptionalTLV
End of LLDPDU TLV
M
…
© 2008 Juniper Networks, Inc. All rights reserved. 19
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
© 2008 Juniper Networks, Inc. All rights reserved. 20
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
© 2008 Juniper Networks, Inc. All rights reserved. 21
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
© 2008 Juniper Networks, Inc. All rights reserved. 22
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
deviceLL
DP-M
EDLL
DP
LLDP-M
ED
1. Interface starts advertising base LLDP TLVs (non-LLDP-MED)
2. LLDP-MED frame sent by neighbor
3. Agent toggles to LLDP-MED
© 2008 Juniper Networks, Inc. All rights reserved. 23
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. 24
LLDP and LLDP-MED Example (1 of 4)
© 2008 Juniper Networks, Inc. All rights reserved. 25
LLDP and LLDP-MED Example (2 of 4)
I’m
a V
oIP
Gat
eway
I’m
an
IP
Pho
ne
I’m
a
switch
I’m a switchI’m
a
switch
I’m a PC
I’m a switch
I’m a switch
I’m a PC
I’m
a
switch
I’m an IP Phone
© 2008 Juniper Networks, Inc. All rights reserved. 26
LLDP and LLDP-MED Example (3 of 4)
xxxx Switchge-0/0/3
………
xxxxIP phonege-0/0/1
xxxxPCge-0/0/2
xxxxGatewayge-0/0/0
InformationDevicePort
xxxx PC/Serverge-0/0/3
………
xxxxIP phonege-0/0/1
xxxxPC/
Serverge-0/0/2
xxxxSwitchge-0/0/0
InformationDevicePort
I’m
a
VoI
P
Gat
eway
I’m a switch
I’m
an
IP
Pho
ne
I’m a PC
I’m
a
switch
I’m
a
switch
I’m a switch
I’m a PC
I’m
a
switch
I’m a switch
I’m an IP Phone
© 2008 Juniper Networks, Inc. All rights reserved. 27
LLDP and LLDP-MED Example (4 of 4)
xxxx Switchge-0/0/3
………
xxxxIP phonege-0/0/1
xxxxPCge-0/0/2
xxxxGatewayge-0/0/0
InformationDevicePort
ManagementApplication
xxxx PC/Serverge-0/0/3
………
xxxxIP phonege-0/0/1
xxxxPC/
Serverge-0/0/2
xxxxSwitchge-0/0/0
InformationDevicePort
SNMP
SNMP
I’m
a V
oIP
Gat
eway
I’m a switch
I’m
an
IP
Pho
ne
I’m a PC
I’m
a
switch
I’m
a
switch
I’m a switch
I’m a PC
I’m
a
switch
I’m a switch
I’m an IP Phone
© 2008 Juniper Networks, Inc. All rights reserved. 28
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; } }}
Determines TTL value sent to neighbor devices
Disables protocol on referenced interface (suggested on untrusted boundaries)
© 2008 Juniper Networks, Inc. All rights reserved. 29
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