SIP lines vs PRI

LaTech · Posted: Wed, 16 May 2007 22:59:06 Post Subject: SIP lines vs PRI

Ok, so this is for the telcom/VOIP/sysadm folks...

Does anyone have either SIP of PRI lines at your place of business?

Are there any Pro's/Con's of using one over the other?

I've heard (granted, from a salesman) that SIP is the new thing...are there any growing pains associate with going with this technology rather than the "tried and true" PRI lines?

I'm in the final stages of making a decision on a new VOIP system for my company, and knowing whether we want SIP or PRI will make a marginal difference in the cost of these systems...so I'm just trying to get some input.

About our system: 70 phones, 2 cities, 3 offices. Will have 2 chassis (one in each city) with fail/roll-over capabilities. Would like to keep our present DID's. Presently on a trunked T1 with multiple dedicated analog lines (faxes etc).

Any info would be appreciated.

BeerCheeze · Posted: Thu, 17 May 2007 00:52:15 Post Subject:

I think he's confused.

SIP = Protocol (Session Initiation Protocol)

PRI = Primary Rate Interface or circuit (T1/ISDN)

So I am not sure what he's trying to sell you?

knight0334 · Posted: Thu, 17 May 2007 08:15:21 Post Subject:

Hell... I'm a Tele/CATV Engineer and I'm confused as to WTF is going on..

(replying back from Windstream Telephone Co. office)

LaTech · Posted: Thu, 17 May 2007 09:07:05 Post Subject:

Ok...maybe I have my accronyms wrong? What we were told was that it was hosted by a ISP rather than a telcom company (in this case, transaria rather than QWest). With SIP as the solution, we have free long distance, could keep DID's etc...

Do I have the wrong info?

BeerCheeze · Posted: Thu, 17 May 2007 10:11:18 Post Subject:

Ok, looking at what I THINK they are talking about is Hosted VoIP (Hosted PBX) -vs- you have having to buy the PBX.

At least that is what I am getting from: http://www.transaria.com/managed_voice_services.htm

Does that sound correct?

LaTech · Posted: Thu, 17 May 2007 10:32:23 Post Subject:

Well, that was one of the options, but we opted not to get that because we lose all control of the system. It would be LIKE that, but instead of it being hosted at a remote site, we would essentially have a PBX here that would run/manage all the VOIP stuff (like a Cisco 7828-H3 running UC Manager 6) but have those kinds of lines running into it. The more I talk about this, the less I think I know...

LaTech · Posted: Thu, 17 May 2007 15:22:43 Post Subject:

Ok, it's SIP Trunking, not SIP lines...

BeerCheeze · Posted: Thu, 17 May 2007 18:22:55 Post Subject:

Took a little bit, but I got it. A SIP trunk is a dedicated circuit just for the SIP traffic. The RTP stream (the actual voice part) go's over your normal internet connection.

At least that is what it appears to be.