[c-nsp] Gut check needed - QoS

[Paul Stewart]

Hi Graham...

That should work just fine...  One minor thing to note by matching UDP port
ranges.. any traffic (not just RTP) that hits those ranges will get priority
.. typically not a big thing but worth mentioning.  In my earlier posting, I
was actually matching by the IP blocks where the softswitch platform
(Metaswitch) is deployed vs port ranges.

Priority will only use bandwidth as it requires it so yes, the default class
will have access to all the bandwidth until something "prioritized" needs
it....

Hope this helps...

Paul


-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Graham Wooden
Sent: September 18, 2009 10:00 PM
To: cisco-nsp
Subject: [c-nsp] Gut check needed - QoS

Hi all,

Paul¹s email from yesterday regarding QoS on a T1 link got me thinking about
a recently deployed PtP T1 serving the same purpose, data/voip to a
customer.  The routers involved on each side are not fancy; my T1 edge is a
2621 and the CPE is a 1760.  The 2621 is hanging off of my 6500/Sup32 that
handles my core stuff.  My softswitches are hanging off of the same chassis.
The CPE 1760 is plugged into switch that has a PIX and a Linksys SPA8000
ATA.

Below is what I had deployed. Pauls email from yesterday and talking with a
good friend earlier confirmed some of this. I reviewed
http://www.cisco.com/en/US/tech/tk543/tk757/technologies_tech_note09186a0080
103eae.shtml to double check the use between Œpriority¹ and Œbandwidth¹.
Priority appears to be a better fit.  Both sides have the same config
applied.  

Does anyone see anything wrong?  I am not 100% sure on the ³ip route-cache
policy² under the serial 0/0. I don¹t see it too often in other configs and
examples.  While this particular ATA does the RTP in a smaller port range, I
like the ACL ranges as I have started to deploy this in other situations
(where RTP is very random between ports 10K and 20K).  And lastly, Is it
safe to assume that the class-default will have access to the full T1 until
calls start rolling through?

TIA,

-graham

-----
class-map match-any VOIP
  description "Prioritize SIP and RTP"
 match access-group 101
!
policy-map VOIP
 class VOIP
  priority percent 50
 class class-default
  fair-queue
!
interface Serial0/0
 bandwidth 1536
 ip address n.n.n.n 255.255.255.252
 no ip unreachables
 no ip proxy-arp
 ip route-cache policy
 no ip mroute-cache
 load-interval 30
 service-module t1 cablelength short 110ft
 service-module t1 timeslots 1-24
 service-policy output VOIP
!
access-list 101 permit udp any any range 4000 5999
access-list 101 permit udp any any range 10000 20000
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/