Avaya's Recommended QoS Configuration

[gknight1]

I was asked by an IT guy if there was a preferred way of configuring QoS on the network that Avaya recommends. Is there a doc or anything out there that i can give them?

This is an entirely local site with all IP phones. The PCs will be plugged into the back of the phones, which will be patched into a switch.

 

[h382]

The default DiffServ is 46. Your IT guys can set his equipment to the same, and you should good.

You can also change these settings under the System Tab in Manager. Click the Help button for more information.

 

[gknight1]

so if i give them that DiffServ setting of 46, they should be able to figure the rest out?

 

[hairlessupportmonkey]

how may phones?

some times its just easier to split the networks between lan1 and lan2

how busy is the network?

QoS can bite you in the ass if you dont set it up properly.

 

[gknight1]

40 phones, its a pretty busy network. I definitely want them to do it right the first time, so the more info I can give them the better.

 

[tanderson3733]

QoS is (as stated) a fairly complex setup, even for some pretty seasoned Network guys. A quick writeup or PDF doesn't really do it justice. BUT, here's some basics.

A lot of times the correct method depends on the network hardware used (Cisco, HP, Extreme, Juniper etc). The Avaya systems and phones are pretty flexible in regards to how they'll interact with a network to allow it to prioritize voice traffic. It's possible you give a network admin something like "Diffserv 46" and he'll look at you like you have 3 heads.

If you're not routing to another location, then you may not be able to use DiffServ settings for a single LAN, depending on certain conditions. 802.1p is typically a Layer 2 priorization method, and you have to ensure that your phones 46xxsettings.txt file tells the phones to tag the packet with the proper value in L2QAUD and L2QSIG (usually 5 or 6, default on the Avaya is 6 but default on most Cisco stuff is 5 - pay attention!)

So regardless of how you're marking your voice packets (802.1p, DSCP) then you have to be able to coordinate that with the network admin. You'll also want to make sure that the network admin understands how QoS/priortization works on a per-port basis. Best results for voice usually entail strict-priority queues, meaning that any time an interface builds up a queue (is congested with packets), voice packets always go right through without any stopping, and data traffic has to wait in the queue until it's clear. Any other types of queues can possibly hold up voice packets, such as round-robin or weighted queues (like 2 voice packets for each data packet, something to that effect) which we do not want.

Hope this gets the ball rolling for you.

 

[Westi]

http://www.ipofficeinfo.com/docs/4600_lan_admin 063008.pdf

That is the guide I give to the IT guys I work with. It has lots of good info in it.
I couldn't find the guide quickly on the Avaya site so that one will do.

Joe W.

FHandw., ACSS

insanity is just a state of mind