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An Unexepected Benefit Of My SIP-to-Cellular Gateway

blackberry-bold-9700-2It’s been a while since I installed the little Portech MV-370 GSM gateway. It sits in the office IT stack and does what it does. When I’m traveling it lets me call home using my unlimited mobile-to-mobile minutes. It also backs up our IP-based home & office phones. If both the Comcast Cable modem and Covad DSL are out the we can route calls out via T-Mobile.

The Gigaset cordless phones support enough accounts that this is easy, just add #6 to the number to specify dial using the GSM trunk. The GSM gateway is the 6th account on the Gigasets. We don’t even need a local Asterisk system to make it possible.

Remembering back to the installation of the GSM gateway, I converted my T-Mobile account from an individual plan to a family plan, with the gateway device becoming the second line on the account. I dropped my number of minutes but the monthly carrying cost was the same. It seems like a good idea since the use of mobile-to-mobile minutes to call home was going to reduce my need for minutes in the end.

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Revisiting A GSM Interface For Your Asterisk Server

Some time ago @Boxdog pointed me to a uCPBX in Bulgaria. They are reselling various small Asterisk systems based upon the Astfin project. They have a few variations on the IP04, including an 8 port variant (IP08 = 8 FXOs) as well as 1 or 4 port BRI capable versions.

ucpbx-astfin-br4-back

The design of the base system supports adding interface ports through the use of little daughter cards. I believe that their daughter cards are compatible with Digium’s TDM-400P card. The cards even use the standard DAHDI driver making installation especially easy.

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Adding A Cellular Trunk To A Home Office VOIP System: Part 2

Originally published June 6, 2008 at www.smallnetbuilder.com

Welcome back! In Part 1, I took you through the thought process that led me to want to add cellular-based access to my home’s VoIP system. I ended up with the following project goals:

  • Ensure the ability to make outgoing calls should our DSL fail
  • Provide access to 911 service
  • Provide access to 411 service
  • Provide a low/no cost way to stay in touch when I’m traveling
  • Provide a means of making oversea calls from my cell phone without paying cellular carriers oversea long distance rates

In this second and final part, I’ll focus on the little box that makes it all possible.

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How To Add a Cellular Trunk to Your VoIP System: Part 1

Originally published May 9, 2008 at www.smallnetbuilder.com

Our Asterisk based home/office phone system provides tremendous flexibility in handling our phone calls. It gave us the opportunity to migrate away from using analog phone lines from a traditional carrier. We now send and receive all calls via IP over our DSL. Of course, the monthly cost of our calling is a lot less. However, it’s not a prefect system – yet.

From the outset, we have worked to make the system more robust. This we have done in many ways, including providing various redundancies in hardware and configuration. Most recently, we have added a cellular trunk to ensure calling capability should our DSL service fail. The process involved in arriving at this decision has proven interesting.

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Portech GSM Gateway: Observations Based On The First 20 Calls

The first part of this week required that I be in Austin, TX working at a customer’s site. This is the sort of trip where I drive to and from as opposed to flying. It’s three hours drive each way, which means listening to XM radio and making phone calls.

A number of times during the period I had to call the UK to consult with associates. As much as possible I tried to do this via the newly installed Portech MV-370 GSM gateway. I’ve made around 20 calls to the UK through the gateway so far.

Remember from our prior installment that have it setup for two-stage dialing, passing incoming cellular calls out through Junction Network’s OnSIP hosted PBX.

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