Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


QOS for Nortel sip trunking in Cisco environment

QOS for Nortel sip trunking in Cisco environment

QOS for Nortel sip trunking in Cisco environment

 I am new to voip and QOS. I need to know what commands to use to give priority for voice traffic being trunked between two nortel signalling servers. THe voice traffic has its own vlan, and we are only installing a few voip phone on desktops, but we are trunking all voice traffic switch to switch across this voice vlan. The switches are a nortel cs1000 and a nortel option 11. The netwqork switches are cisco 4006 and 6500 with an additional 6500 acting as a router. Sorry about the neophyte questions. I just need some guidance and most posts are about configurations for the phone devices.

RE: QOS for Nortel sip trunking in Cisco environment

We use Nortel VoIP across our Cisco Routers.

I'm not sure what Cisco uses, but nortel uses DSCP EF for Voice and CS5 for Signaling traffic. There is a lot of information about this in Nortel's documentation "Converging the Data Network with VoIP" http://support.nortel.com/go/main.jsp?cscat=DOCDETAIL&id=744268&poid=12514 - Page 76 talks about the DSCP mechanisms.

Now we've implemented QoS on our routers, but I don't know how it would relate to the Multi-Layer Switches and whether or not the 6500 uses similar commands (If it runs IOS, it probably does)... however I can post a sample qos config if need be and we can go from there.

RE: QOS for Nortel sip trunking in Cisco environment


Thank you so much for this post. Yes a sample configuration fiile would probably be very helpful.

thanks again

RE: QOS for Nortel sip trunking in Cisco environment

This is a sample QoS Config we use on our Cisco Routers

class-map match-any Nortel-Signaling
 match  dscp cs5
class-map match-any Routing-1
 match  dscp cs6
class-map match-any Nortel-Voice
 match  dscp ef
policy-map NortelVoIP
 class Nortel-Voice
  priority percent 16
 class Nortel-Signaling
  bandwidth percent 4
 class Routing-1
  bandwidth percent 5
 class class-default

interface FastEthernet0
 service-policy output NortelVoIP

If your connection between the routers is not shaped / limited, it's pretty straight forward (in this case, for a 100mbps link, 16Mb/s would be provided as priority for voice traffic, 4mbps, is guaranteed for nortel signaling and 5mbps is guaranteed for routing protocols).

If you DO have a trottled connection, then we need to add a couple bandwidth commands and shape the traffic before it's sent out (relatively straight forward)

RE: QOS for Nortel sip trunking in Cisco environment

@ gm85

Not sure if you'll be able to answer this, but we have a straight forward set of Bonded-T1's that connect sites.  We have QoS setup similar to what you have above setup for that link on a Multilink interface.  We just recently set up a Backup route using a Cable Modem on either site's end, and connecting them via an IPSec Tunnel.  I've tinkered a bit with what to do, but am not sure if i am in the right directions.  The linke is 1Mb Up 3Mb down on either side, so assuming 1 meg on either side, what bandwidth/priority levels do you think we should set?  

I followed this article from Cisco but things are slightly different because this is on two routers with the IPSec IOS:

class-map match-all Data_New
  match protocol ipsec
  match input-interface Tunnel1
  match input-interface Tunnel2
  match input-interface Tunnel3
class-map match-all Voice_New
  match  dscp ef
  match  dscp cs5
policy-map Voice_Policy_New
  class Voice_New
  class Data_New
   police 200000 37500

Chris (CapnDoody)

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members!

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close