!!! Overview [{$pagename}] ([CCS]) or in the [United States] also [common-channel interoffice signaling] ([CCIS]), is the transmission of signaling information (control information) on a separate channel than the [data], and, more specifically, where that signaling channel controls multiple data channels. For example, in the public switched telephone network (PSTN) one channel of a communications link is typically used for the sole purpose of carrying signaling for establishment and tear down of telephone calls. The remaining channels are used entirely for the transmission of voice data. In most cases, a single 64kbit/s channel is sufficient to handle the call setup and call clear-down traffic for numerous voice and data channels.[4] The most common [{$pagename}] signaling methods in use today are [Integrated Services Digital Network] ([ISDN]) and [Signalling System No. 7] ([SS7]). !! More Information There might be more information for this subject on one of the following: [{ReferringPagesPlugin before='*' after='\n' }]