[c-nsp] Gut check needed - QoS

[Graham Wooden]

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