>>I know they have a presence in SS7 technology. I'm a laymen so any help would be appreciated, I believe this technology is the piece that puts a phone and data signal thru the phone at a managed output?....I believe SS7 is the kingpin in this issue, but need to know alot more.<<
John, the SS7 Signaling System is an ITU Standards derivative, and is actually an entire separate data network that runs side by side, kinda, to the public switched telephone network, or PSTN.
SS7 is probably the single largest network in the world that is continuously running with a highly structured, defined purpose, and at the same time, it is probably the least understood or least disseminated technology in all of telecomm. Up until recently, only those in the deepest trenches of the telcos had a need to understand it.
SS7 performs link and switch-element surveillance, look-ahead pre-testing and signaling prior to a call set up, the actual call set up itself, supervision of audible tones such as busy and ringing... it does a lot of smart things in order to ensure that quality connections are established.
SS7 is said to be an "out-of-band" signaling arrangement, since the signals it employs do not occupy the same channels as those which actually make up the call connection. Instead, it exists as a meshed overlay of X.25-like lines spanning the entire reach of the switching infrastructure. Ordinarily, one must qualify as a carrier with the regulators and possess a Carrier ID Code, or CIC, in order to make use of it, through a hierarchy of "links." Prior to SS7, you may recall, calls took much longer to set up, and you could actually "hear" the "in-band" signaling multi-tones taking place.
SS7, in conjunction with advanced information network, or AIN databases, also performs functions that enable selective use of special resources which are tied to individual accounts. Such as 800 calling, 800-redirects, pre-paid call accounting pointers, calling line identification (CLID), automatic number identification (ANI), call forwarding, follow-me, special billing and accounting functions, you know the variety. It accomplishes this through a series of connections or "links" from the telco's switching platform to a highly specialized Information Network which is comprised of service control point databases, or SCPs. SCPs are specialized databases that are scattered about the network, also tied together with SS7 links. The SCP databases contain account information (custom instructions per account number, carrier IDs, billing timers, privileges, rights, histories, pointers to resources, translation services, etc.).
On the smaller programmable switches such as the Excel and SUMA switches, these data bases are usually local host systems (Unix and NT database servers) tied directly to the switch that can be customized to accommodate just about any custom feature imaginable, whereas many of the big iron switches such as the LU 5E-ESS and the NT DMS100 require lengthy code rewrites and revision intervals. The SCPs are also tied together by SS7, just like the switching service points on switches. It's a net thrown on top of a net, so to speak. But none of this SS7 stuff is ever tied directly into the lines you speak over. SS7 just does the surveillance, instruction execution, and overall orchestration.
HTH, Frank Coluccio
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