[cisco-voip] VoIP Deployment Questions

[Jared Mauch]

On Mon, Oct 27, 2003 at 11:13:24AM -0500, MPuras at solunet.com wrote:
> Hi all.  I am in need of some guidance regarding uptime, packet loss and
> latency for national / international VoIP network.  We will be rolling out a
> VoIP network.  The first phase of the deployment will consist of getting the
> customer HQ located in Boca Raton, Fl. and one of the remote offices located
> in Los Angeles.  LA will have a fractional T1 to the local POP and Boca will
> have a full T1 at the main office to the local POP.  We will have VPNs
> between the remote offices and the HQ.  Future deployment will also include
> New York and London.  All packets (voice and data) will leave the network in
> either location as a standard IP packet.  I am in the process of looking at
> a few different carriers and selecting one for this national / International
> VoIP rollout. QoS end-to-end is a big concern for me.
> 
> One of the carriers I am looking claims that it guarantees a 99.97% uptime
> and no more than .05% packet loss during any calendar month.  However they
> do not offer QoS.  
> 
> Is this consider acceptable for a VoIP deployment?  What sort of uptime and
> latency and packet loss should I be looking for?  Would you still require
> QoS if the network utilization of the carrier is half of its capacity?
> 
> Any recommendations for carriers?

	My experience is that no QoS is not necessary at all.  The
key is that they have sufficent bandwidth on their network
to carry the traffic and do not perform any (significant) packet
reordering.

	As part of the inoc-dba project <http://www.pch.net/inoc-dba>
i've participated in multi-country international VoIP calls where
there is no QoS involved and some people are behind cable modems
or other providers that do not offer QoS.  We've seen no 
problems with voice quality.  The key is to insure there is sufficent
bandwidth for a constant bitrate of 88.2k/s (with g711ulaw codec - 64k
data plus ip packet overhead).  Outside of that most people can not
tell the difference between VoIP and a PSTN telephone link.

	- jared

-- 
Jared Mauch  | pgp key available via finger from jared at puck.nether.net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.