What are the advantages of SIP trunks versus analog circuits?

SIP trunking is not perfect, but it has more options and features compared to what traditional phone companies offer, says UC expert Matt Brunk.

What are the advantages SIP trunks versus analog circuits?

Analog trunks conduct harmful voltages; they can be disrupted by bad weather and it's difficult to get good support when you need service. Also, if you are not a large enterprise customer with contractual pull, be prepared to stand in line.

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I abandoned our company's analog trunks in 2010 after implementing test Session Initiation Protocol (SIP) trunks in 2008. I did this because I was sick of dealing with the phone company, and I subsequently cut costs by 60%. That decision didn't come lightly, and when we implemented an IP-PBX in the fall of 2008 for our office's test bed, we did so with SIP trunks and the only connection to that system was a patch cable to our LAN switch. After running SIP trunks for over a year and experiencing the pros and cons, it was a no-brainer: Goodbye analog, hello SIP trunks.

But the aforementioned advantages are only partial reasons to fully embrace SIP trunks. When a business needs presence in another town, city, state or country, SIP trunking is the way to accomplish this. SIP trunks are easier to deal with than any traditional telephone company. As a provider, I'd had enough of the old analog circuits. Clients that paid my firm to act on behalf of them simply because they refused to interact with the phone company are a testimony to the advantages of SIP.

You've heard the overall advantages of SIP trunks: They use better technology, are faster to deploy and cheaper than alternatives. Now let's discuss SIP speed. Large enterprises are concerned about saving time -- as should any business -- large or very small. SIP trunk calls are processed faster. There is less ringback time (waiting for the dialed number to start ringing) and time-to-ring (time the call actually rings at the dialed number/destination). Less time means less occupancy on that virtual channel, and this translates to less bandwidth.

Because you must build in longer ringback and time-to-ring times, in analog telephony you may need to design in more analog trunks simply because you will have higher utilizations. For really small firms this may not be a big deal, but for firms with large trunk groups, the times add up. When you integrate voice and data over one pipe (bandwidth) it means you have one access facility to deal with. This doesn't take away the ability to install built-in backup. In fact, you can retain one or more analog trunks and failover to them. You can also failover to cellular service or to other company locations. The beauty of this is that with SIP trunks, you have more options and features compared to what traditional phone companies offer.

Moving phone services via SIP trunks is painless. We've moved scores of companies over the decades, and SIP has allowed us to move a PBX without delay. There may be an IP address change issued to the SIP provider, but nothing earth shattering really takes place when you move except for the hassle of moving the office. I can also pare down or scale up with a single phone call, and I can do this as often as I would like. This translates to right-sizing and keeping costs in check. The audio on SIP trunk calls is as good, if not better, than analog. This doesn't mean SIP trunks are perfect, but the few hassles are worth the savings.

In early July 2013, we initiated an order with a new SIP provider that ported our numbers over to a hosted PBX and integrated the numbers to ring on our SIP trunks into our PBX. We did this after testing the service for several months, and because we would save even more money with our new provider.

With analog trunks you usually have one provider unless it's a choice of CLECs (competitive local exchange carriers) offering a T1 with an analog adapter. This way I have more choices than with a telco or CLECs. With our new provider, I've found that we can make suggestions and they will either say, "We can't do that, we already do that or maybe we should do that."

Companies that fail to leverage the benefits of SIP trunks are giving money away to the traditional telcos. Done right, SIP trunks will have you looking ahead and not back at the not-so-good old days of the PSTN.

For more information: Check out this tip on SIP trunk service advantages.

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