Description

This article provides an example of how to advertise CoS setting in LLDP-MED Network Policy TLV for voice VLAN.
 

Solution

Refer to the following step-by-step example.


Step-1 : Define classification for forwarding class. In this example, traffic with DSCP code point 101110 and dot1p 101 should go to assured-forwarding, and 101111 should to network-control.

set class-of-service classifiers dscp test import default
set class-of-service classifiers dscp test forwarding-class assured-forwarding loss-priority low code-points 101110
set class-of-service classifiers dscp test forwarding-class network-control loss-priority low code-points 101111
set class-of-service classifiers ieee-802.1 test1 forwarding-class assured-forwarding loss-priority low code-points 101


Step-2 : Apply this CoS on the interface where the phone is connected to handle the incoming traffic in the proper queue:

set class-of-service interfaces ge-0/0/2 unit 0 classifiers dscp test
set class-of-service interfaces ge-0/0/2 unit 0 classifiers ieee-802.1 test1


Step-3 : Notify phone to send the traffic with proper tag (DSCP or dot1p). When forwarding class assured-forwarding is configured under switch-options for interface ge-0/0/2, LLDP-MED will send DSCP value 46 and dot1p 5, as defined above in CoS (Step-1 and Step-2).

root@juniper# show switch-options
voip {
    interface ge-0/0/2.0 {
        vlan cos-voip;
        forwarding-class assured-forwarding;
    }
 
# set switch-options voip interface ge-0/0/2.0 vlan cos-voip >>>>>> LLD-MED will advertise the VOIP vlan (41) to the phone connected port ge-0/0/2
# set switch-options voip interface ge-0/0/2.0 forwarding-class assured-forwarding >>>>>> LLD-MED will advertise the forwarding class code-point to the phone connected port ge-0/0/2
# set class-of-service classifiers dscp test forwarding-class assured-forwarding loss-priority low code-points 101110
# set class-of-service interfaces ge-0/0/2 unit 0 classifiers dscp test
 

Verification:

On the interface connected to phone, classifier ‘test’ was applied, and under switch-options assured-forwarding class for VOIP VLAN was defined on interface ge-0/0/2. Assured forwarding class code-point is 101110 (46).
root> monitor traffic interface ge-0/0/2 extensive no-resolve >>>>>> interface connected to the phone
Address resolution is OFF.
Listening on ge-0/0/2, capture size 1514 bytes
 
21:51:54.945792 Out
        Juniper PCAP Flags [Ext], PCAP Extension(s) total length 16
……..
          LLDP-MED Capabilities Subtype (1)
            Media capabilities [LLDP-MED capabilities, network policy, location identification, extended power via MDI-PSE] (0x000f)
            Device type [network connectivity] (0x04)
          0x0000: 0012 bb01 000f 04
        Organization specific TLV (127), length 8: OUI ANSI/TIA (0x0012bb)
          Network policy Subtype (2)
            Application type [voice] (0x01), Flags [Tagged]
            Vlan id 41, L2 priority 5, DSCP value 46 >>>>>>>>
          0x0000: 0012 bb02 0140 536e
        End TLV (0), length 0
^C
1 packets received by filter
1 packets dropped by kernel
 

Example 2:

# set switch-options voip interface ge-0/0/2.0 vlan cos-voip
# set switch-options voip interface ge-0/0/2.0 forwarding-class network-control
# set class-of-service classifiers dscp test forwarding-class network-control loss-priority low code-points 101111
# set class-of-service interfaces ge-0/0/2 unit 0 classifiers dscp test
 

Verification:

On interface connected to phone, classifier ‘test’ was applied, and under switch-options network-control class for VOIP VLAN was defined on interface ge-0/0/2. Network-control forwarding class code-point is 101111 (47).

root> monitor traffic interface ge-0/0/2 extensive no-resolve
Address resolution is OFF.
Listening on ge-0/0/2, capture size 1514 bytes
 
22:08:09.581544 Out
        Juniper PCAP Flags [Ext], PCAP Extension(s) total length 16
……..
          LLDP-MED Capabilities Subtype (1)
            Media capabilities [LLDP-MED capabilities, network policy, location identification, extended power via MDI-PSE] (0x000f)
            Device type [network connectivity] (0x04)
          0x0000: 0012 bb01 000f 04
        Organization specific TLV (127), length 8: OUI ANSI/TIA (0x0012bb)
          Network policy Subtype (2)
            Application type [voice] (0x01), Flags [Tagged]
            Vlan id 41, L2 priority 0, DSCP value 47 >>>>>>>>
          0x0000: 0012 bb02 0140 522f
        End TLV (0), length 0
^C
1 packets received by filter
0 packets dropped by kernel
 
 
Note: If any configuration is missing in switch-options or COS, LLDP-MED will send the DSCP value as ‘0’.