SIP vs. TDM....digital vs IP

[mobiledynamics]

I'm sure this question is carrier dependent or that I'm just a bit sensitive to sound/noise quality but in your opinion, do you feel a TDM circuit & or a ~digital phone~ as opposed to IP via the PBX will always produce the best sound quality.

On the flipside, I have used SIP services like Vonage and Callvantage - in addition to even SIP based phones like the Polycoms and the sound quality IMO has been excellent.

I'm reading older threads on a phone system we're considering to get, and part of the equation is the phones. For flexibility, IP phones all the way. But a couple of threads in the IPOffice forum suggest that the digital handsets do just sound better in general from a SQ/VQ than their respective IP handsets.

Just pondering, thinking . Same goes to the SIP vs TDM. I'm looking at all options such as TDM via Paetec or SIP trunked options via curryip & global xo and bandtel.

 

[kwing112000]

I think you will find that the sound with VOIP can be good. there are a lot more factors that come into play on how it sounds. You have to make sure you have good network gear for it to sound good. It also takes a little while to get used to the differences in sound. I have put in a lot of VOIP and it sounds good in most cases. but every once in a while you get sites that will never sound great. I think going VOIP really depends on your business and how critical your phones are. the VOIP is more succptable to problems.

Kevin Wing
ACA- Implement IP Office
Carousel Industries

 

[mforrence]

My opinion is that TDM/Digital combo is always going to provide better sound quality. It is a mature technology. VoIP MAY be as good, but also may not.
Mike

 

[Sympology]

Depends, seriously.

If you have good network, pleanty of bandwidth. Running G711 then I (and everyone I know) find the calls much better than traditional calls. However, the chances are at somepoint you will have to leave the nice corporate LAN / MAN and go through a carrier. This is where things start to degrade. You likely to have to use a more compressed CODEC, get more dropped packets etc etc.

VOIP will superceed TDM eventually, but when? Down to the ISP's and carriers really and how much money they are willing to invest.

Only the truly stupid believe they know everything.
Stu.. 2004

 

[pabxdude]

Avaya provides wideband audio on there 96 series phones.
this provides sound quality that is better than the traditional TDM.

g722 is the codec from memory.

 

[mobiledynamics]

FWIW,I'm been doing some testing. Not side by side to a digital phone, but I can hear the difference on digital 4621sw on g711 codec - t1 tdm terminated onto a IPO . Just testing.

Interestingly enough, from prior experience on a polycom via hosted sip, it was very clear and did not sound digital at all.

OR it could be my damm golden ears - kinda how I prefer a warm sounding tube amp at home.

On a side note, is the Polycom HD all that cracked up to be ?