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

Petr Lapukhov, 4xCCIE/CCDE
About Petr Lapukhov, 4xCCIE/CCDE

Petr Lapukhov has more than 12 years of experience working with Cisco Systems products. Not only is he the only person in the world to have earned four CCIEs (Routing & Switching, Security, Service Provider, and Voice) in just two years, he also passed every exam the first time. He shares his knowledge and experience with INE’s students through our various products and programs. Petr works with all of the technologies covered within his four CCIE tracks on a daily basis, staying current with any changes in the industry. He has also received his Cisco Certified Design Expert (CCDE) certification, joining a small group of distinguished individuals who have achieved this status. Petr is a contributor to INE’s blog and our INE IEOC Community Forum. You may contact Petr Lapukhov at petr@ine.com.

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