Jan
21

As first and very basic option, you may use Generic Traffic Shaping to implement FRTS. This is a common technique, not unique to Frame-Relay, with the following properties:

- Configured by using traffic-shape interface command
- As with standard GTS, internal shaper queue is basic WFQ
- Configured per inteface/subinteface (no PVC granularity)
- GTS may adapt to BECNs & reflect FECNs (BECN received at any interface/subinteface PVC will cause shaper rate to throttle back to minCIR)
- FECN reflection activates sending BECNs in responce to incoming FECN frames. Note, that FECN/BECN responce requires provider to mark frames with FECN/BECN bits
- You can configure Fancy-Queueing (WFQ/PQ/CQ) at physical interface level with GTS.

Example:

!
! Physical Interface, fancy-queueing may apply here
!

interface Serial 0/0/0:0
no ip address
encapsulation frame-relay
fair-queue

!
! Subinterface, apply GTS here
!

interface Serial0/0/0:0.1 point-to-point
ip address 177.0.112.1 255.255.255.0
!
! Shaping rate
!
traffic-shape rate 512000
!
! "MinCIR", adapt to BECNs
!
traffic-shape adaptive 256000
!
! Reflect FECNs as BECNs
!
traffic-shape fecn-adapt
frame-relay interface-dlci 112

Verification:

Rack1R1#show traffic-shape

Interface Se0/0/0:0.1
Access Target Byte Sustain Excess Interval Increment Adapt
VC List Rate Limit bits/int bits/int (ms) (bytes) Active
- 512000 3200 12800 12800 25 1600 BECN

Rack1R1#show traffic-shape statistics
Acc. Queue Packets Bytes Packets Bytes Shaping
I/F List Depth Delayed Delayed Active
Se0/0/0:0.1 0 157 10500 0 0 no

Rack1R1#show traffic-shape queue
Traffic queued in shaping queue on Serial0/0/0:0.1
Queueing strategy: weighted fair
Queueing Stats: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/32 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 512 kilobits/sec

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