Legacy FRTS & Subinterfaces

FRTS and subinterfaces. This page follows on from the previous article on legacy FRTS configuration here and shows the default behaviour of FRTS with subinterfaces.

The legacy frame-relay traffic shaping has to be enabled on a physical interface. Any subinterfaces will then inherit the configuration, which is 56kbps by default. The network is shown below:



In the example below FRTS is turned on but not configured, both subinterfaces are then shaped to 56kbps (using screenshots as the output to "show traffic-shape" doesn't like this sites layout).

R1#show run | begin interface Serial0/0
interface Serial0/0
no ip address
encapsulation frame-relay
no fair-queue
clock rate 2000000
frame-relay traffic-shaping
!
interface Serial0/0.102 point-to-point
ip address 192.168.12.1 255.255.255.0
snmp trap link-status
frame-relay interface-dlci 102
!
interface Serial0/0.103 point-to-point
ip address 192.168.13.1 255.255.255.0
snmp trap link-status
frame-relay interface-dlci 103

As shown below, the target rate is 56000b/s



This config sets a map on one of the subinterfaces shaping it to 2mbit:

map-class frame-relay TEST_MAP
frame-relay traffic-rate 2000000 2000000


interface Serial0/0.102
frame-relay class TEST_MAP

The remaining subinterface remains at 56kbps:



You can apply the map to the physical interface, the sub-interfaces then inherit these settings:



Applying other maps to the subinterfaces overrides any inherited settings:

map-class frame-relay TEST_MAP_2
frame-relay traffic-rate 128000 128000


interface Serial0/0.103
frame-relay class TEST_MAP_2