The code developed by an appliance marker that enables Asterisk to interact nicely with enterprise firewalls could eventually do much much more. That's because this is open source.

by Alex Goldman ISP-Planet Managing Editor [January 27, 2006]

This week, Morganville, N.J.-based Ranch Networks announced the development of security code for Asterisk, the open source VoIP project, that allows enterprises to combine Asterisk with Ranch appliances. The code is certified by Huntsville, Ala.-based Digium and is available in the latest Asterisk version, number 1.2.3.

The code uses a standard developed by the IETF called Middlebox Communications to open firewall ports only when a call is actually in progress. This should make enterprise firewalls far more secure.

Ram Ayyakad, CEO of Ranch, calls this "dynamic firewall control", and it is already a part of the latest Asterisk core, v. 1.2.3. It will also be available as an integral part of the next major Digium release. For the moment, Ayyakad admits, "we are still working with Digium to clarify a few things. The challenge was to put our code into the core of Asterisk."

The benefits are numerous, Ayyakad says. "It's really good bulletproof security, hardware based queuing, the ability to segregate data and voice, bridging, and there's no proprietary thing going on."

Kevin Fleming, senior software engineer at Digium of co-maintainer of Asterisk (with Mark Spencer, Asterisk's author and the CEO of Digium), says Digium insisted that the protocols Ranch used be open. "We're very very strict about architectural issues," he explains. "The initial implementation was very Ranch Networks-centric. We said that the implementation needed to be as generic as possible."

So other vendors could plug in the same capabilities? "Yes," says Fleming. "If they didn't use MIDCOM, they could use other protocols. The vendor would provide a module that speaks their protocol to the firewall."

It works
We ask Ayyakad how his company has tested the appliance, and he replies that Ranch has been using the system in its office for four months. The company has fifteen different kinds of phones, testing all of the industry standards, and none, he says, have been a problem. "We're thrilled," he says.

Digium is also very happy. Fleming cannot yet talk specifics, but he says that the Asterisk vendor community is starting to imagine applications for the technology that Digium and Ranch had not anticipated.

So expect more news on the same subject later this year.

Pricing and availability
The code is open source and free. Ranch Networks appliances vary depending on number and type of ports, with prices ranging from about $750 to over $25,000.

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