QOS for Nortel sip trunking in Cisco environment 1

[mrj25]

Hello,
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.

 

[gm85]

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.

 

[mrj25]

gm85,

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

thanks again

 

[gm85]

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
fair-queue
random-detect

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)

 

[CapnDoody]

@ 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:

http://www.cisco.com/en/US/customer...s_configuration_example09186a008080dfa7.shtml

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
priority
class Data_New
police 200000 37500


Cheers,
Chris (CapnDoody)