Can we have SIP trunking with our TDM PBX?

By Robin Wilding
Updated: February 08, 2011

So you quasi-recently invested in a TDM PBX only to find out that telephony is moving at the speed of light and that TDM PBX system has already become outdated. Many companies invested in TDM PBX back in 1999 and still have years of life left in the hardware but are dying to upgrade to a cheaper SIP trunking solution. These companies are now wondering if they can salvage their TDM investment but still add SIP trunking to their existing infrastructure. Good news.

It is possible to use your legacy TDM PBX solution alongside SIP trunking, while still maintaining the benefits and features of both.

How the heck?

The process will be quite simple if you have available TDM trunk ports…but most likely you do not. To route a new SIP trunking solution through your TDM you need to make a “drop and insert” style installation by placing a media gateway into the TDM trunk circuit. You will need to insert the media gateway in-between the TDM and PBX so that one side of the gateway is facing the TDM and the other side the PBX. The gateway will essentially go unnoticed as it will simply route traffic from one appliance to the other, but it is an essential ingredient.

Now you need to setup your SIP trunking solution and terminate it along with the TDM on the media gateway that you have just installed. When you have successfully completed this circuit you will have both the TDM and SIP terminating on the newly installed gateway. Routing tables will now be cleverly shuffling the calls between the circuits.

This new solution should also provide a failsafe in that if either the TDM or SIP fails the service will roll-over completely to the service still running. If both the TDM and SIP fail then you are stuck.

This solution however is resting on the fact that your PBX is SIP-ready. If by chance your PBX is not SIP-ready as you are running a key system or traditional analog then you will need to install an integrated access device.

This solution is surprisingly easy to install and configure but will give you a few more years of use from your TDM before you switch entirely over to a SIP trunking solution.

Costs

You already laid out a whack of dough for the TDM solution so it is important that the integrated SIP Trunking solution not require too much outlay. The initial costs to integrate your existing TDM PBX with an SIP trunking solution are minimal. The important ingredient that you need to purchase is a media gateway, which should cost between $1,000 to $5,000 depending on your data volume and the brand of hardware that you choose. Then you have the cost of the SIP trunk implementation, which will vary depending on the solution you choose.

Featured Research
  • 7 Ways the Wrong Phone System Can Haunt Your Business

    The wrong phone system could be haunting your business - and we’re talking about problems more serious than ghosts and ghouls. From increased costs to issues with scaling, we’ve identified seven important ways that a less than ideal phone system could be holding you back. You’ll be surprised at how much of a difference this can make to your bottom line too. more

  • Ditch Your Fax Servers

    An in-house fax server gives an IT department centralized management and monitoring over the entire enterprise's faxing. This can help your company track usage and better maintain records for auditing and record keeping. However, there are serious drawbacks that come with utilizing an in-house fax server solution and these range from security to cost-prohibitive pricing. more

  • The IT Manager's Survival Guide

    As an IT manager, maintaining physical fax servers and infrastructure is not a high priority. However, fax capability remains a business need simply because chances are your industry is dependent on its security. What if there was a way to reduce the amount of time spent handling fax complaints and maintaining physical servers? And this way took into account security, cost savings, and freed up your IT resources. Would you be interested? more

  • VoIP: Your New Secret Weapon for a Strong Year End

    As the end of 2017 nears, you may be feeling pressure to make sure you close the year out strong.If you’ve been sitting on the fence regarding VoIP, this may be the perfect time to switch. VoIP options had never been better or more full-featured than they are now, and it may be just the thing your business needs to see a productivity and profitability boost. more

  • Is Your Phone System Stealing Profits?

    Having the wrong phone system can dramatically cut into your profits. Despite this, many businesses just sign up for a plan or platform that seems ‘good enough’. If you haven’t carefully considered your options and the included features, there’s a very good chance that you are leaving money on the table in some way. more