Cisco Frame-Relay Traffic Shaping Fragmentation

Cisco Frame-Relay Traffic Shaping Fragmentation

These values are recommended for fragment sizes on low speed links:

56 Kbps==> 70 bytes

64 Kbps==> 80 bytes

128 Kbps==> 160 bytes

256 Kbps==> 320 bytes

512 Kbps==> 640 bytes

768 Kbps==> 1000 bytes

1536 Kbps==> 1600 bytes

For example, if we have 256kbps Frame-Relay link, our fragment size will be 320 byte.Then we do not experience serialization delay more than 20 ms.

Here is a sample configuration:

class-map match-all voip
 match  dscp ef
!
policy-map LLQ-test
 class voip
  priority percent 50
 class class-default
  fair-queue
!
map-class frame-relay FRTS-Test
 frame-relay cir 256000
 frame-relay fragment 320
service-policy output LLQ-Test
!
interface Serial0/0
 no ip address
 encapsulation frame-relay
 frame-relay traffic-shaping
!
interface Serial0/0.1 point-to-point
 ip address 10.10.10.1 255.255.255.252
 snmp trap link-status
 frame-relay interface-dlci 100  
  class FRTS-Test