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RE: VOIP + PPP + QOS posted 09/11/2003
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Bola,

	With that kind of bandwidth, serialization delay is a problem for sure.
Fragmenting like Scott mentioned should help.  If in fact you're using
encryption, that's going to add a little more delay.  This RAN 64/25, is it
a WIC serial interface, or an external device you attach to via ethernet or
normal serial connection?  Since you're doing MLPPP, I assume it's serial
out of the router.  You might want to try compression on the PPP as well.
The RTP won't compress at all, but everything else will.  I had good luck
doing that at a bank with 56kb frame PVCs, with voice, ATM, and data traffic
to each branch.  Or use RTP header compression.  What's the distance between
these routers?    If it's less than 25 miles and a clear line of site, you
might want to look at 802.11a/b bridges.

Chuck Church
CCIE #8776, MCNE, MCSE
Wam!Net Government Services
13665 Dulles Technology Dr. Ste 250
Herndon, VA 20171
Office: 703-480-2569
Cell: 703-819-3495
cchurch@xxxxxxxxxx
PGP key: http://pgp.mit.edu:11371/pks/lookup?search=chuck+church&op=index

-----Original Message-----
From: Bola Adegbonmire [mailto:BolaAD@xxxxxxxxxxxxxxxxx]
Sent: Thursday, September 11, 2003 4:49 AM
To: Charles Church; ccielab@xxxxxxxxxxxxxx; Brian Dennis
Subject: RE: VOIP + PPP + QOS


RAN64/25 is a 64 Kbps radio over 25 KHz channels.
IOS running is C2600-is56i-mz-120-18.bin. So bandwidth is no where near T1.
Traffic: remote site accesses the HQ over the link and traffic is mainly
from client machines to Lotus notes server at HQ. users have no internet
connection. Basically it is the Voice and data been uploaded and downloaded
to/from Lotus notes server.

IOS limitations due to 12.0 is major constraint. Lack of memory(Flash/NVRAM)
does not allow IOS upgrade. When it gets choppy I believe is when they are
flei tarnsfers are taking place which is quite frequent as comapnay is a
bank and all servers reside at HQ location. Remote site is part of HQ, but
due to lack of space some employees had to be at another physical site.

Regards,

Bola

-----Original Message-----
From: Charles Church [mailto:cchurch@xxxxxxxxxx]
Sent: Wednesday, September 10, 2003 3:00 PM
To: Bola Adegbonmire; ccielab@xxxxxxxxxxxxxx; Brian Dennis
Subject: RE: VOIP + PPP + QOS


I figured out what RAN is, but I'm not sure what the 64/25 refers to.  What
is the bandwidth of this radio network?  If it's approaching T1 speed or
above it, serialization delay shouldn't affect the voice quality.  Voice is
fine up to about 100 ms delay.  What kind of traffic is on the line?  What
IOS are you running?  With the right version, you could use NBAR to monitor
and/or rate limit to a pretty high detail.  When you say it's clear at
times, and choppy at other times, what activities are occurring on the
network when it gets choppy?  IP accounting may be of use also.  HTH.

Chuck Church
CCIE #8776, MCNE, MCSE
Wam!Net Government Services
13665 Dulles Technology Dr. Ste 250
Herndon, VA 20171
Office: 703-480-2569
Cell: 703-819-3495
cchurch@xxxxxxxxxx
PGP key: http://pgp.mit.edu:11371/pks/lookup?search=chuck+church&op=index

-----Original Message-----
From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx]On Behalf Of
Bola Adegbonmire
Sent: Wednesday, September 10, 2003 9:00 AM
To: ccielab@xxxxxxxxxxxxxx; Brian Dennis; Charles Church
Subject: VOIP + PPP + QOS


Hi all,

I have a situation with two routers (2611 running ) connected via a wireless
link using RAN 64/25. voice network is connected via E&M ports with Avaya
definity on one end and Alcatel on the other side.

All is set up but I have QOS issues on line. Due to IOS limitations I can
only do custom-queueing/priority queueing

Presently I am using ip rtp rpiority.
1 The line is quite clear atimes and atimes it breaks. My suspicion is that
serialization delay causes this inspite of Ip rtp priority

I wanted to use a multilink interface to set ppp LFI and fragmentation delay
but IOS does not support multilink interfaces (i.e interface multilink1)

I am looking at way for doing LFI so that serialization delay is withing
acceptable but I have looked at the options are I can thik of can't see any
that satisfies. Pls any ideas?

also due to congestion issues ring back is not heard atimes and caller just
hears called party saying hello. This I believe is due to TCP call setup and
tear down channels going within normal queue. I was wondering if it was
possible for me to have priority queueing on same interface as ip rtp
priority. reason I am thinking of this is so that I can put only the setup
channel within this queue so that users hear the call alerts whatever
congestion situation is.

Pls any bright ideas to help me out.



Bola Adegbonmire
Networks
Resourcery Limited
18 Adeola Hopewell, Victoria Island.Lagos-Nigeria.
Tel:234-1-3200301, 4618281, 7740711-2 ( Ext:1644)

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