E.T wanna call home (over the internet)

March 10, 2007 3:22 AM

Internet Telephony Query: What combination of hardware and software runs JaJah.com?

JaJah allows you to make a call from a web line to a telephone line using your own number. My question is this: How exactly are they doing this? Is it possible to clone something like that using freely or commercially available software, or does one have to home roll everything?

Did they reach deals with all the telecom companies? Do they have a huge server farm making calls, or hundreds of modems?

How exactly does it work?

posted by markovich to computers & internet (8 comments total)

The phone system backbone is all digital now, so at the JaJah HQ they have a rack of PCs connected to a multi-channel digital phone line such as a T1 (24 voice lines) or ISDN PRI (23 voice lines). Or, more likely, an even bigger pipe such as a T3 or OC-3. Actually, they probably have more than one point of presence for outbound calls, or if they don't have many, they may have a peering agreement with other VOIP provider(s) to use theirs. More than likely they are running a customized version of Asterisk to provide the actual service.
posted by kindall at 4:53 AM on March 10, 2007

JaJah allows you to make a call from a web line to a telephone line using your own number. My question is this: How exactly are they doing this? Is it possible to clone something like that using freely or commercially available software, or does one have to home roll everything?

The fastest way to setup your own VoIP company is to (1) license codecs from GIPS and (2) buy PSTN connectivity from RNK. Then code up your own client software. Depending on your business objectives and design decisions, you may or may not need to develop your own SIP servers.

Did they reach deals with all the telecom companies? Do they have a huge server farm making calls, or hundreds of modems?

I don't know about JaJah specifically, but many tier-1 telecom providers have made large investments in VoIP equipment, both for their own networks and to sell as a service to their customers. A startup won't have the volume necessary to justify writing a contract with Global Crossing, so they are more likely to go with RNK until their volume ramps up.

Done right, VoIP is not a capital intensive business for a startup.

There is no need to worry about DS1/DS3 or OC3 links. Any modern colocation facility will provide you with a standard gigabit ethernet link, and you will connect via IP to your telecom service provider(s).
posted by b1tr0t at 8:16 AM on March 10, 2007

My lack of knowledge might be causing me to misread this, but..

using your own number

I think that is the key question being asked. All the other information so far is very useful as context, but it doesn't explain why Jajah can do something Skype doesn't.

I think the answer is that Jajah phones you, and phones the destination number, and their equipment and service agreements act as a bridge between the two phone lines. Any VOIP provider could do the same, see all the context above.

How Jajah gets the caller ID information correct, if it does, is another question..
posted by Chuckles at 11:01 AM on March 10, 2007

Last I heard, caller ID spoofing was trivial.
posted by cmonkey at 11:20 AM on March 10, 2007

Well, with VoIP, anyway.
posted by cmonkey at 11:21 AM on March 10, 2007

I think the answer is that Jajah phones you, and phones the destination number, and their equipment and service agreements act as a bridge between the two phone lines. Any VOIP provider could do the same, see all the context above.

That is one of the reasons why you might want to develop your own SIP server.

In general, the answer to questions of the form "why does VoIP provider XXX provide service AAA, but provider YYY doesn't" is that the business models for provider XXX and YYY require different feature sets. SIP is a remarkably flexible protocol. A team of engineers could spend decades writing cool SIP apps. The tricky part is coming up with features that customers want, then marketing them. The engineering is the easy part.

Last I heard, caller ID spoofing was trivial.

It depends on the equipment involved, but usually you can either advertise any number you want, or any number that you advertise will be rejected.
posted by b1tr0t at 11:31 AM on March 10, 2007

Yeah, if you have a home VOIP service and an unlocked telephony adapter, you can change the Caller ID name as you like. The only reason you wouldn't be able to change the number too is that it's your user ID to log in to the VOIP provider's network. It's all just numbers sent over the network.
posted by kindall at 11:59 AM on March 10, 2007

The telephony portion of Jajah is built on top of the open source Asterisk PBX, which runs on commodity PC hardware.

A reasonably competent programmer who's familiar with Asterisk's call manager subsystem can clone the important bits of Jajah in a few hours (I know this, because I've done this). Actually connecting the calls and spoofing the caller ID and such are all fairly trivial operations. The rest is really just a reasonably decent web interface.

As for terminating the calls, it's possible that they've made arrangements with traditional telecom providers, but it's more likely that they've made arrangements with VoIP termination providers (think: voipjet), such that Jajah's servers don't actually touch the PTSN -- they're just routing IP traffic.
posted by toxic at 3:18 PM on March 10, 2007