06-15-2006 03:21 PM - edited 03-03-2019 01:01 PM
I need to configure QoS, and think what I am trying to do is very simple, but am starting to see cross-eyed when reading all of Cisco's documentation on ways to implement QoS. Could someone please point me in the right direction? Here is the story: We have 2 sites which are connected with a point-to-point T1. We have Cisco 2620 routers at each site. We have Catalyst 2950 switches at each site. We have phone switches at each site which are connected via IP. What I want to do is: I want to prioritize the switch ports that the phone switches connect to at each site, and I want the routers to recognize that marked traffic and give it priority. That's it. There must be a very simple way to do this. Help please! I am going to search thru other topics, too, to see if this has been posted before. Much appreciation for any help!!!
Steve
06-15-2006 03:59 PM
Hello Steve,
I too think QOS is a really hard job.
But, tell me are those cisco ip phones?
if so,
easy set up on the 2950 would be:
cdp enable
mls qos trust device cisco-phone
mls qos trust cos
and on the routers would be something like:
ip cef
class-map match-all voiceip
match ip precedence 5
policy-map policy1
class voiceip
priority #
interface fa0
service-policy output policy1
Hope this help a bit,
Vlad
06-16-2006 02:37 AM
Dont forget to also mark your signalling traffic
class-map match-all sig
match ip precedence 3
06-16-2006 06:45 AM
Hi Vlad,
Actually, they are NEC phone switches. The phones themselves are regular digital units, it is the actual switches themselves which communicate via TCP/IP. That is what makes me think it shouldn't be all that hard. What I have tried is setting the cos to 5 on the ports the NEC switches connect to on our Catalyst 2950s. The router part is what confuses me, so the router config sample you said looks helpful. I will give it a try. Thank you for your response!
Steve
06-22-2006 10:45 AM
Hi Steve,
If you want to read about it, look up Low Latency Queuing, which Vlad gave you an example of above. For signalling traffic, you would use Class Based Weighted Fair Queuing, which is configured just like LLQ except it uses the bandwidth instead of the priority command. There used to be a limit of how much traffic could be assigned to the priority queue, 70 or 75% if I remember correctly.
Have fun,
Tom
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