The purpose of these trials was to assess the revenue potential of services that depend on deployment of the common channel signaling network needed to transmit the calling number between originating and terminating central offices.
32.
The common channel is the portion of small intestine, usually 75-150 centimeters long, in which the contents of the digestive path mix with the bile from the biliopancreatic loop before emptying into the large intestine.
33.
In 1981, AT & T introduced its Common Channel Interoffice Signaling ( CCIS ) network and the Network Services System ( NSS ) database for providing its own centralized facility for Toll-Free Number translation and service provisioning.
34.
Shannon's channel coding theorem shows that over many common channels there exist channel coding schemes that are able to transmit data reliably at all rates R less than a certain threshold C, called the channel capacity of the given channel.
35.
It was during this period that AT & T's network was converted to Common Channel Signaling, the switching machines were replaced with 4ESS digital switches, the first fiber optic cables were installed, and the network was being converted to Dynamic Nonhierarchical Routing.
36.
The Internet Engineering Task Force ( IETF ) defined SIGTRAN protocols so the common channel signaling paradigm could be translated to IP Message Transfer Part ( MTP ) level 2 ( M2UA and M2PA ), Message Transfer Part ( MTP ) level 3 ( M3UA ) and Signalling Connection Control Part ( SCCP ) ( SUA ).
37.
RFC 2719 also defines the concept of a " signaling gateway " ( SG ), which converts Common Channel Signaling ( CCS ) messages from SS7 to SIGTRAN . Implemented in a variety of network elements including softswitches, the SG function can provide significant value to existing common channel signaling networks, leveraging investments associated with SS7 and delivering the cost / performance values associated with IP transport.
38.
RFC 2719 also defines the concept of a " signaling gateway " ( SG ), which converts Common Channel Signaling ( CCS ) messages from SS7 to SIGTRAN . Implemented in a variety of network elements including softswitches, the SG function can provide significant value to existing common channel signaling networks, leveraging investments associated with SS7 and delivering the cost / performance values associated with IP transport.
