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2Apr/110

TDM Card Kit – Transcoding SS7 DACS

I've built large systems with this but there seems to be nothing in the small TDM space for experimentation with TDM data on the telco network.  I'll be working on a simple 1-4 DS1 version first starting with the framers and FPGA.  If you are interested in working on this open source project drop me a line.

As of 04/02/2011 I'm planning on using the DS2155 framer to a basic plugin card.  Eventually these will be plug in cards to add DS1's to the main FPGA/DSP board.

30Dec/091

SS7 – A-Link M3UA MTP2 . Now what?

Well if you have been following along you either have a M3ua link up and running or you really want one, peeking ahead to see what it'll do.  Well my first application was something very simple.  I wanted to do my own CNAM lookups so I built a small TCAP query interface.  It  allowed me to pass a DN via IP and returned the Callers Name. Very useful when you have  a VOIP switch and want to provide real cnam.  

30Dec/090

SS7 – A working A link. From MTP2 to M3UA.

I won't go into the basics of SS7 here but here is a quick tutorial to get you started if you need help.

http://pt.com/page/tutorials/ss7-tutorial

At this point I assume you have a A Link or two of them, some hardware including some type of interface card like a Sangoma A101. If you have the gear, I prefer to use commercial gear to get m3ua rather than a link to the PC when possible.

I normally use the CentOS distro because its easy to get, has all the components and is very stable.  Main things you'll likely need in it are development tools and lksctp.

With the sangoma card you'll want to download and install the mtp2 driver.  There is sample code included and instruction on getting the MTP2 layer up and running.

29Dec/090

SS7 Getting started with a Link – The overview

One of the biggest hurdle in working with SS7 is getting a link in a form to work with.  Normally at most CLEC's, it comes in on a 56k DDS line or if you are lucky its one of the channels (56k) on a DS1 line.  Sangoma has the A101 card as well as MTP2 driver for linux that works great at getting the SS7 link into something you can use.  If you have a DDS version of the link you'll need a bit of Adtran or other gear to convert this to a DS1 and map it to a channel so the A101 can talk with it.   Once you get the link to a PC thats where the magic happens.

29Dec/092

SS7 for the common person…

Many of you that know me are aware I've been pretty deep in the telephony world for quite some time. Everything from putting fiber into the ground to SS7 links.  Over the years I've written a lot of code to do SS7 messaging and signaling either for gateway type applications or full blown ss7 data servers.  Many have inquired about wanting SS7 but had no real understanding of what they wanted and certainly didn't want to pay to figure it all out.   I still think there is a void there between commercial full blown SS7 and the SS7 tinkerer.  This article will an introduction be for the latter.