Telecom Advice for 3CX Newbie - SIP vs PRI

[bigdummy]

Hi All,

Our company is opening a new office, with about 15 employees, and we're looking at using 3CX for our phone system.

I'm looking for advice on whether we should use a SIP provider like NexVortex, or if we should use a PRI and gateway. What are the pros and cons for each scenario?

We're planning on getting bonded T1 internet service at 6Mbps, which I assume should be enough to handle internet and SIP/voice, for up to 15 users.

But before I order the service, I just wanted to see if there would be any benefit to getting a T1 just for internet, and a separate PRI for voice.

Any other related advice for a total n00b is also welcome...

Thanks!

 

[craigreilly]

We have a Nexvortex account that I used for initial testing of our system while the old pbx was still using our T1 trunk. It semed to work fine for 3 or 4 calls at a time. It never got above that usage. But the calls were clear. No complaints.

Do you know what kind of traffic your users will generate phone call wise? Will all 15 ever be on a call at the same time?
What kind of traffic will they generate data wise on their computers that might affect the NexVortex trunk?

The NexVortex is probably cheaper than the PRI - monthly, as well as the added cost of a Gateway for the PRI.

 

[lneblett]

Good question actually.

The greatest difference between the 2 is price, with Sip trunking providers having the edge. There are other things to consider as well:

PRI service is technology that has been around for some time and as a result, is generally deemed to be the more reliable. As it is dedicated, it is not subject to the issues that sometimes arise with an Internet carrier service...your voice data is not competing for space like it might on the Internet.

Sip is more apt to use cable Internet service providers as the carrier. Most cable companies have not yet exhibited the same level of reliability, but they have and are improving by leaps and bounds as evidenced by their own marketing of business class services and increasing use of fiber and redundant systems. Some are better than others so am not able to suggest that all are great. I have used cable in a number of locations with excellent results and I have a couple of customers who converted to cable and SIP and wished they had done so far earlier. There are a number of excellent sip providers, nexVortex, Broadvox, vitelity to name few.

One downside to a PRI is the need to buy and configure an interface card. As far as t1 for Internet, I guess it just depends on if you can live with the limited bandwidth. If you have cable or even dsl or even wireless carriers available, I would personally look at the options before committing to t1. The price to speed factor may influence you to try sip before you commit to PRI.

Do not forget about alarm systems, fax machines, postage meter heads (if you download postage), credit card machines and analog modem needs.

 

[jpillow]

I guess this question is best answered on two different factors. What type of bandwidth is available, just T1s? Cable providers of so which providers. The cost savings obviously are with SIP but whats most important for your company the "familiar" or unfamiliar. What are your other data needs other than just the voice voice. I'd sample SIP trunks at first and see how that works out for you on average most companies only use 20% of their lines at any given time so with 24 pri channels that's only about 5-6 calls at any given time so that would indicate to me enough bandwidth. However being that industry standard doesn't mean it's your organizations standards. At the end of the day it's what works best with the chosen vendors, available services, and company usage.

 

[bigdummy]

Thanks for the replies everyone...

I'm not sure how much phone traffic there will be. It's not going to be a call center, but I imagine there may be a handful of people on the phone at random times throughout the day. It'll mostly be an office for management and accounting types, who typically have a lot of conference calls with people outside the company.

In regards to Internet/Data bandwidth usage, I think we'll be fine with 4 or 5 Mbps of bandwidth. Faster would be better, but the problem is that our only options are T1 and maybe cable (I'm waiting for a site survey from Time Warner to confirm if cable is an option). We're about 13,000 feet from the local CO, so metro-E, fiber, DSL, are not available.

If we go the T1 route, it'll plug into a Cisco router, so I'm assuming I can do some QOS stuff to guarantee bandwidth to the SIP traffic?

We don't have any organization standards. Some offices have a PBX system and PRI, most offices use a hosted VoIP provider. We're looking to start standardizing and get all offices on 3CX over the course of the next year or so, as the hosted VoIP contracts expire.

What about alarm systems, fax machines, etc...how would 3CX handle those, or is better to just get some PSTN lines that connect directly to the alarm/fax?

Thanks again!

 

[lneblett]

You might also check with any local WISP providers, but hopefully TWC will come through. I just hate to see what your bonded t1s will cost.

In any event, QOS doesn't sound as though it will get utilized much. Your description of the site and its use lead me to think that internally you have adequate bandwidth for everything and more. Once the traffic has left the router and made it on to the internet carrier, QOS is no longer a factor....first come, first served; otherwise everyone would simply try and prioritize their traffic over all others. In any event, nothing will be hurt by using it anyway. You will need to coordinate with your T1 provider about how to best prioritize traffic while in their carriage....should you go this route. You may want to give some thought to remote extensions as well.

Alarm systems, fax machines and analog dialup modems are best off with PSTN lines. Credit card machines can largely be replaced using card swipes on pc with a receipt printer and using the Internet. Check with your card clearing house provider. Postal meter heads also may come with a USB cable for attachment to a pc and downloading via the Internet rather than with their built-in analog modem.you simply need to check, but in any event you can use one PSTN line to do multiple tasks as none of the aforementioned use a line for long periods and alarm systems should be able to cut-in and sieze the line if a need arises.

 

[leejor]

In regards to Internet/Data bandwidth usage, I think we'll be fine with 4 or 5 Mbps of bandwidth.

Be sure to confirm that this is symmetrical (same speed both directions). Some providers offer a much lower upload speed.

 

[bigdummy]

Thanks again for the advice. I'll definitely check on Wireless ISP's too. We used a WISP at another office (different state) and the connection was solid as a rock. But we weren't using it for voice traffic, so I can't comment there...

The 4 bonded T1's are a symmetrical 6Mbps up & down. Megapath quoted us $930 per month, which is pretty good based on my experience. We're paying close to $500 for a single T1 at some of our other offices.

 

[ZenMasta]

I recently switched from pots to all voip in June.
I'm using cable internet 30 down/5 up in the office and our dedicated server is hosted elsewhere with 100mbps up/down. We're still saving money compared to when we were all pots. I think I've only ever had 4 concurrent calls but I have not experienced any any call quality issues.

For me I was concerned with the potential outage you might experience with cable so that plus our dedicated server with a usualy 99.9 SLA makes me feel pretty comfortable. I feel comfortable this would work for us if we had an outage at the office I could create a backup IVR with ringgroups that would ring our cell phones instead etc.

Two other extensions are using residential cable also and they're just fine too.

I'm using nexvortex you get unlimited channels you only really have to worry about your 3cx license and your minute pool.

Tech support has always been very responsive. The only thing I don't like is their billing system.