Re: Frame-relay Traffic-shaping on subinterfaces only

csteinman · ‎04-15-2002

I am trying to set up QoS over frame relay, but am running into problems with the "frame-relay traffic-shaping" command. The problem is that I don't have control over the routers on the other end of 2 of my 6 PVCs (although I can configure them if I don't mess up anything beyond my PVC). I want to run traffic shaping on 4 PVCs but disable it on the other 2, since they both go to interfaces on the distant routers which also have PVCs to routers that can't handle frame-relay traffic-shaping. I know that traffic shaping must be applied to the whole interface, but is there a way to do the same thing on subinterfaces? If I enable traffic shaping on my router I run into thoughput problems on the routers without traffic shaping.

Here is my config:

!

ip multicast-routing

!

class-map match-all VoIP-Control

match access-group 101

class-map match-all VoIP-RTP

match access-group 100

!

policy-map voip-policy

class VoIP-RTP

priority 100

class VoIP-Control

bandwidth 8

class class-default

fair-queue

!

call rsvp-sync

voice rtp send-recv

!

interface FastEthernet0/0

description Prescott Cortez Office LAN

ip address X.X.X.X 255.255.255.0

speed auto

full-duplex

!

interface Serial1/0

description Qwest, Frame Relay

bandwidth 768

no ip address

encapsulation frame-relay

no fair-queue

cdp enable

frame-relay lmi-type cisco

frame-relay ip rtp header-compression

!

interface Serial1/0.16 point-to-point

description PVC to Chino Valley, 768 CIR

bandwidth 768

ip address X.X.X.X 255.255.255.252

ip ospf network broadcast

frame-relay interface-dlci 16

class voip

frame-relay ip rtp header-compression

!

interface Serial1/0.18 point-to-point

description PVC to Camp Verde, 768 CIR

bandwidth 768

ip address X.X.X.X 255.255.255.252

ip ospf network broadcast

frame-relay interface-dlci 18

class voip

frame-relay ip rtp header-compression

!

interface Serial1/0.19 point-to-point

description PVC to Phoenix, 128 CIR

bandwidth 128

ip address X.X.X.X 255.255.255.252

ip ospf network broadcast

frame-relay interface-dlci 19

!

interface Serial1/0.20 point-to-point

description PVC to Prescott, 768 CIR

bandwidth 768

ip address X.X.X.X 255.255.255.252

ip pim sparse-dense-mode

ip ospf network broadcast

frame-relay interface-dlci 20

class voip

frame-relay ip rtp header-compression

!

interface Serial1/0.22 point-to-point

description PVC to Flagstaff, 756 CIR

bandwidth 768

ip address X.X.X.X 255.255.255.252

ip ospf network broadcast

frame-relay interface-dlci 22

!

interface Serial1/0.23 point-to-point

description PVC to Whipple, 768 CIR

bandwidth 768

ip address X.X.X.X 255.255.255.252

ip pim sparse-dense-mode

ip ospf network broadcast

frame-relay interface-dlci 23

class voice

frame-relay ip rtp header-compression

!

ip pim bidir-enable

!

map-class frame-relay voip

frame-relay fragment 1000

no frame-relay adaptive-shaping

frame-relay cir 768000

frame-relay bc 1000

frame-relay be 0

frame-relay mincir 768000

service-policy output voip-policy

!

access-list 100 permit ip any any precedence critical

access-list 101 permit ip any any precedence flash

Robert Salazar · ‎04-15-2002

Frame-relay traffic shaping is enabled on the main interface, and it applies to all DLCIs under that interface. We cannot enable traffic shaping only for a particular DLCI or subinterface under the main interface. If a certain DLCI has no map class attached to it, and traffic shaping is enabled on the main interface, the DLCI is assigned a default map-class with CIR = 56000.

You can create a separate map class for the two other pvc's. This map class defines the cir at the normal "burst: rate telco would allow you to send on a best effort basis and the mincir at the guaranteed rate.

More at this link:

http://www.cisco.com/warp/public/125/traffic_shaping_6151.html

aacole · ‎04-19-2002

My solution to this is not to use FRTS but to use GTS instead. The benifits are that you can run GTS with WFQ, and also specify the individual PVC parameters. You only enable GTS on the sub-interface, not on the physical port.

EG using part of your config

interface Serial1/0

description Qwest, Frame Relay

bandwidth 768

no ip address

encapsulation frame-relay

fair-queue

cdp enable

frame-relay lmi-type cisco

frame-relay ip rtp header-compression

!

interface Serial1/0.16 point-to-point

description PVC to Chino Valley, 768 CIR

bandwidth 768

ip address X.X.X.X 255.255.255.252

ip ospf network broadcast

frame-relay interface-dlci 16

frame-relay ip rtp header-compression

traffic-shape rate 1536000 192000 0

traffic-shape adaptive 768000

traffic-shape fecn-adapt

This config allows the link to burst to 1536k bps, and falls back to cir of 768k in event of congestion notification. Obviously the actual values depend on access speeds and frame contract. Also I set the 2nd value (192000) to be the first value divided by 8 for a time constant of 125mS.

csteinman · ‎04-19-2002

Thank you. I'll try this, although there is a warning in the documentation that says by the time a becn is received, voice is already degraded. But what else can I do short of buying another circuit? I'm going to be installing another circuit later this year, so this will be a temporary fix.

Changed one line to:

traffic-shape rate 1536000 20000 0 to lower the delay to closer to 10 ms.