• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 737
  • Last Modified:

Qos for T1 customer using hosted Internet PBX

Greetings,

I provide T1 service to a customer that is subscribed to a SIP Trunking provider.

Their T1 terminates on a PC-MC-T3 slot on a 7206VXR/NPE-G2

Their T1 device is an Adtran TA912 IAD using FXS interfaces to their legacy PBX.

The customer complains that the remote caller's voice is choppy and gets cutoff, sometimes to an extreme point.  The remote caller hears my customer's voice just fine.

My customer has requested we implement QoS  for SIP on their T1 and to a Fast Ethernet interface on the same router that connects to the Internet, and we have no problem doing that as we anticipate similar customer needs increasing.

What is the best method to provide QoS on PPP-Multilink, inbound and outbound, and the inbound from the public Internet.  The adtran seems pretty flexible and the customer wil handle that configuration, but I need some help on the Cisco end for a configuration to place inbound/toubound on T1 interfaces and inbound w/ what I am guessing will be packeting marking for RTP and SIP?

Thanks,

D
0
chikagoh
Asked:
chikagoh
  • 7
  • 5
1 Solution
 
Rick HobbsRETIREDCommented:
Here is the portion of a config file for Auto-QOS for a 7206:
class-map match-any AutoQoS-VoIP-RTP-Trust
 match ip dscp ef
class-map match-all going-pc
 match access-group 121
class-map match-any AutoQoS-VoIP-Control-Trust
 match ip dscp cs3
 match ip dscp af31
class-map match-all bla
 match ip rtp 16384 16383
!
policy-map AutoQoS-Policy-Trust
 class AutoQoS-VoIP-RTP-Trust
  priority percent 70
 class AutoQoS-VoIP-Control-Trust
  bandwidth percent 5
 class class-default
  fair-queue
!
interface Serial5/4:1
 no ip address
 encapsulation frame-relay
 no fair-queue
 no arp frame-relay
 frame-relay traffic-shaping
 frame-relay lmi-type ansi
 frame-relay intf-type dce
!
interface Serial5/4:1.1 point-to-point
 ip address 10.3.180.14 255.255.255.252
 no arp frame-relay
 frame-relay interface-dlci 104
  class AutoQoS-FR-Se5/4:1-104
  auto qos voip trust
!
interface Serial6/2:1
 no ip address
 encapsulation frame-relay
 no fair-queue
 no arp frame-relay
 frame-relay traffic-shaping
 frame-relay lmi-type ansi
 frame-relay intf-type dce
!
interface Serial6/2:1.1 point-to-point
 ip address 10.3.180.10 255.255.255.252
 no arp frame-relay
 frame-relay interface-dlci 103
  class AutoQoS-FR-Se6/2:1-103
  auto qos voip trust
!
map-class frame-relay AutoQoS-FR-Se5/4:1-104
 frame-relay cir 1536000
 frame-relay bc 15360
 frame-relay be 0
 frame-relay mincir 1536000
 service-policy output AutoQoS-Policy-Trust
!
map-class frame-relay AutoQoS-FR-Se6/2:1-103
 frame-relay cir 1536000
 frame-relay bc 15360
 frame-relay be 0
 frame-relay mincir 1536000
 service-policy output AutoQoS-Policy-Trust
!
rmon event 33333 log trap AutoQoS description "AutoQoS SNMP traps for Voice Drops" owner AutoQoS


0
 
chikagohAuthor Commented:
Does this sample configuration translate to PPP?  Not using Frame at all.

Is autoqos reliable enough>
0
 
Rick HobbsRETIREDCommented:
Yes.  Exactly the same replacing the frame config with PPP config.  And AutoQOS on the PIX should work fine for your needs.
0
Free recovery tool for Microsoft Active Directory

Veeam Explorer for Microsoft Active Directory provides fast and reliable object-level recovery for Active Directory from a single-pass, agentless backup or storage snapshot — without the need to restore an entire virtual machine or use third-party tools.

 
chikagohAuthor Commented:
This isn't a pix though, it's a 7206VXR/NPE-G2.  The Pix doesnt even have T1 interfaces right?? eek
0
 
Rick HobbsRETIREDCommented:
I am sorry. I meant to say 7206.  I have been working on a PIX 515e with failover problem all day.  The config is for a 7206.  Just change the frame config to PPP and you should be cooking.
0
 
chikagohAuthor Commented:
Its ok, I've neem there.  I'm sure you know what your doing, but I need to make sure I am 100% clear.

1) Your frame examples are ALL customers facing?
2) Do I need to mark SIP packets inbound on my public Internet connection, or is this going to be done going down the customer facing T1?

3) What goes under the map classes in place of the frame cir/bc/be/minicir

4) Since I will be using PPP, what do I want to disable at the interface level?  (Proxy, unreachables, etc.. etc..).  Use fair queue or not?

5) On Multilink interfaces, do I want fragment and interleaving?  What to disable?  Fair queue?

Thanks,

D
0
 
chikagohAuthor Commented:
also, whats the acl for 121?
0
 
chikagohAuthor Commented:
Also, map-class is only good for atm, dialer and frame.  No ppp.
0
 
Rick HobbsRETIREDCommented:
You are correct.  Actually PPP is much simpler.  As long as you have Cisco Express Forwarding turned on, you just need to make sure that the AutoQoS feature works correctly. Configure it in this order: Enter the bandwidth command first and then the auto qos voip trust command.  I work a lot with the Avaya products and usually refer to:
http://www.avaya.com/master-usa/en-us/resource/assets/applicationnotes/autoqos.pdf  to implement.  It should be the same with whatever voice system you are using.
0
 
chikagohAuthor Commented:
I ran across the avaya doc along the way and it was helpful.  It's great that auto qos will automatically configure a multilink interface on a low speed link (768k or less), but doesnt provide much info when bundling multiple T1s together.

I think the only thing left is to find a way to set dscp for SIP and RTP going to to the T1 customer since they are getting them unmarked from the public Internet.

Does 'match protocol' for SIP and RTP really work?  RTP can use such a broad range of ports?
0
 
Rick HobbsRETIREDCommented:
Yes, the cisco implenetation on the 7206 works very well.
0
 
chikagohAuthor Commented:
Do want to set the packets as they come into the router from the public Internet, or do I want to set the packets on the customer facing T1?

What would be a good config to set the packets so they match the auto qos settings?
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

  • 7
  • 5
Tackle projects and never again get stuck behind a technical roadblock.
Join Now