03-07-2006 01:46 AM - edited 03-03-2019 11:57 AM
Heres what I'm looking to accomplish. We currently have 2 T1's with a CIR 1024 per T1. I would like to setup traffic shaping to handle congestion. What would be the best way to go about this? Or, where should I start? We are currently utilizing CEF load balancing (per packet).
Thanks,
joel-metz
Solved! Go to Solution.
03-13-2006 05:37 PM
By default, the router assumes the Bc to be the cir. This could get you into trouble during periods of congestion as you would oversubscribe the PVC big time.
You need to configure the bc to 48000 assuming you are going to use the CIR of 1536000. There are 32 Tc intervals when the CIR is set to 1536k. If you do the math here, 1536000/32 it comes out to 48000.
To verify your work, do a 'show frame pvc (dlci)' and it should look like something below.
R1#show frame-r pvc 102
PVC Statistics for interface Serial0/0 (Frame Relay DTE)
DLCI = 102, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0.1
input pkts 11 output pkts 4188 in bytes 644
out bytes 349129 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 4112 out bcast bytes 343581
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
pvc create time 05:03:15, last time pvc status changed 05:01:47
cir 1536000 bc 48000 be 0 byte limit 6000 interval 31
mincir 1024000 byte increment 5952 Adaptive Shaping none
pkts 290 bytes 23928 pkts delayed 0 bytes delayed 0
shaping inactive
traffic shaping drops 0
Queueing strategy: fifo
Output queue 0/40, 0 drop, 0 dequeued
Check out the following example on CCO and it should make more sense.
http://www.cisco.com/en/US/tech/tk713/tk237/technologies_configuration_example09186a00800942f8.shtml
Let me know if it helped.
--Sundar
03-07-2006 01:46 AM
Hi Joel,
How many DLCIs do you have per T1 ? That, and the CIR for each of them, will determine how you shape your traffic out.
Paresh
03-13-2006 04:49 PM
Thanks Paresh for a quick response!
We have one DLCI per T1 circuit. They both have a CIR of 1024.
HTH
joel-metz
03-13-2006 04:55 PM
Then it's easy...
Here's what you can do:
interface Serial0/0:1
no ip address
encapsulation frame-relay IETF
load-interval 30
no fair-queue
frame-relay traffic-shaping
!
interface Serial0/0:1.16 point-to-point
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 16
frame-relay class Shape1024k
!
map-class frame-relay Shape1024k
frame-relay traffic-rate 1024000 1024000
Do the same for the other T1 and you are done !
Hope that helps - pls rate the post if it does.
Paresh
03-13-2006 04:58 PM
Paresh,
What about handling congestion notifications, throttling back when this occurs? Also, do I need to configure the home end as well?
Thanks,
joel-metz
03-13-2006 05:02 PM
If you are getting BECNs from your provider, you can do the following:
interface Serial0/0:1
no ip address
encapsulation frame-relay IETF
load-interval 30
no fair-queue
frame-relay traffic-shaping
!
interface Serial0/0:1.16 point-to-point
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 16
frame-relay class Shape1024k
!
map-class frame-relay Shape1024k
frame-relay cir 1536000
frame-relay mincir 1024000
frame-relay adaptive-shaping becn
With the above config, your router will attempt to shape out at 1536k, the T1 max rate. If it starts receiving BECNs, it will drop down to a minumum of 1024k.
Yes, you do need to configure both ends.
Paresh
03-13-2006 05:37 PM
By default, the router assumes the Bc to be the cir. This could get you into trouble during periods of congestion as you would oversubscribe the PVC big time.
You need to configure the bc to 48000 assuming you are going to use the CIR of 1536000. There are 32 Tc intervals when the CIR is set to 1536k. If you do the math here, 1536000/32 it comes out to 48000.
To verify your work, do a 'show frame pvc (dlci)' and it should look like something below.
R1#show frame-r pvc 102
PVC Statistics for interface Serial0/0 (Frame Relay DTE)
DLCI = 102, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0.1
input pkts 11 output pkts 4188 in bytes 644
out bytes 349129 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 4112 out bcast bytes 343581
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
pvc create time 05:03:15, last time pvc status changed 05:01:47
cir 1536000 bc 48000 be 0 byte limit 6000 interval 31
mincir 1024000 byte increment 5952 Adaptive Shaping none
pkts 290 bytes 23928 pkts delayed 0 bytes delayed 0
shaping inactive
traffic shaping drops 0
Queueing strategy: fifo
Output queue 0/40, 0 drop, 0 dequeued
Check out the following example on CCO and it should make more sense.
http://www.cisco.com/en/US/tech/tk713/tk237/technologies_configuration_example09186a00800942f8.shtml
Let me know if it helped.
--Sundar
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