Nortel Wireless Phones

[RookThis]

Does anyone know what COS value a Nortel phone marks for signaling and audio?

 

[biv343]

DSCP 40 for call setup, 46 for payload.

If it's a 221X phone, the data is encapsulated in SVP, which is protocol ID 119.

 

[RookThis]

Thx for the response... Just for my understanding, so if it's a 221phone, then all I would see is SVP protocol 119? This communication will just be between the phone and a 2245, right? If that's the case, how is QoS handled if the 2245 is across a LAN spanning multiple switches? I was expecting to see a COS or DSCP value to enable me to define some sort of QoS.

 

[biv343]

You should see DSCP info between the media card and SVP. You should see Spectralink packets between the phone and SVP.

The SVP protocol is protocol ID 119. You can match on that.

Also make sure the switch ports are trusted, otherwise your DSCP/SVP headers might get stripped.

 

[RookThis]

Is there some documentation that explains this? Thanks again for the response... but info I've gotten and it's starting to make sense! Thx!

 

[biv343]

The WLAN installation/maintenance guide has some info. Also, Spectralink has some decent info, but it takes some digging to find.

 

[RookThis]

Can you please explain one additional thing. You stated, "You should see DSCP info between the media card and SVP". What do you mean by this, is this on the 2245 side? I did a trace on the wireless side and I couldn't see the DSCP marking. I did see the ID 119, but I expected to see a DSCP or COS in the headers. What media are you referring to?

Thanks again, as you can tell I am not very familiar with the nortel devices.

 

[biv343]

IF you put a sniffer between the media card and 2245 (mirror one of the ports), you should see DSCP information in those packets. You'll see SVP from the phone since the traffic is "encapsulated" in SVP at that point.

 

[RookThis]

Thanks again, I guess what I'm trying to figure out is how to go about implementing QoS from the handset to the 2245, since the handsets and the 2245 are in two different campuses and span mutliple network devices and network segments.

Is this what you mean when you say place a sniffer between the 2245 and media card, if so, the QoS is set at that point after leaving the 2245, but what happens before that? That's the piece that I'm unclear about.

handset<====>2245<===>sniffer<===>media-card

It appears that the phone just knows about SVP and nothing else from what I can tell. I was trying to implement QoS end to end, by either COS or DSCP prior to hitting the 2245. I can do this with some class maps and match on IP addresses but that will include the signaling and media and maybe more.


I appreciate your time, and I thank you for the information. It's been a bear trying to figure out how this works.

My Sincere Regards!

 

[biv343]

It does complicate things with SVP thrown in there. But, in a few more years we probably won't need the SVP servers anymore.

What I usually do is prioritize against the DSCP values as well as the SVP protocol ID. That has worked out fairly well for me. Also make sure your AP's are configured to recognize the SVP protocol and treat the SVP traffic appropriately. Wireless is shared medium, so that's about the best you can do there.

Or you could do as you mentioned and put the wireless phones on their own VLAN, then prioritize against the IP addresses that are in that VLAN.