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SS7 Over the Ring Introduction
Overview
The SS7 over the EXNET ring software enables the use of four SS7 stacks on the ring. Only voice data travels on the ring to remote nodes. Communication between nodes is done over the Ethernet for all command and control information, which allows connection of the voice path on the ring, so that EXNET is fully available for maximum voice traffic.
Important! When the term SS7 card appears in this text, it applies to both the SS7 PQ card and the SS7 Series 3 card.
The following application conditions apply to an installation and operation of SS7 over the ring:
• An SS7 PQ card supports up to four nodes through a single Signaling Point (SP).
• An SS7 Series 3 card supports up to seven nodes through a single Signaling Point (SP).
• A maximum of four SS7 protocol stacks per SS7 card (or pair)
• Required termination of the signaling links on the SS7 Server Node
SS7 cards that are operating in a redundant card pair as a single SP must be installed in adjacent slots in the same chassis.
Using modified system software, a single Server Node (up to four nodes on an SS7 PQ card, up to seven nodes on an SS7 Series 3 card) can appear to function in the network as a single Signaling Point (SP) with a single Originating Point Code (OPC).
Single Server Node implementation of SS7 over the ring offers the following advantages:
• An increased number of voice channels supported by a single SP with the redundancy offered by the EXNET ring architecture.
• No changes to host API messages
• The same level of functionality provided with the SS7 Fault Tolerant Redundancy.
SS7 Over the EXNET Ring Software
When a call is setup, the signaling data is carried using SS7 out-of-band from the voice channels. Dedicated Ethernet links are required at the SS7 connection in order to get the signal from the signaling network to the channels, ensure synchronization, and provide instructions. In summary, the signaling data commands the phone to ring and gives instructions on the SS7 network. This information is shared with all other remote nodes using the Ethernet connection.
The SS7 over the ring software is functionally equivalent to the existing SS7 card, including the protocol variants that are supported, the limitations, API messaging, configuration, and other functions.
• The SS7 over the ring software can be used to control CICs in remote nodes in a CSP.
• The SS7 software offers increased processing power.
Within Excel’s CSP, a primary requirement for Central Office environments is enabled: a fully redundant architecture with optional redundancy at the card level.
Each node in a multiple node CSP supports up to 2048 non-blocking ports in:
• Central Office environments
• Distributed switching
• Wireless Local Loop (WLL)
• In-building wireless applications
• Service platforms
• Wireless infrastructure
• Long distance, debit card, callback, and call center operations
Within an SS7 network architecture there are three major components:
Service Switching Points (SSP) are CSPs that perform call processing on calls that originate, tandem, or terminate at the CSP.
Signal Transfer Points (STP) are CSPs that relay messages between network CSPs and databases.
Service Control Points (SCP) are CSPs that contain centralized network databases, which provide enhanced services.
The SS7 card permits the CSP to act as an SSP in an Advanced Intelligent Network (AIN). The SS7 card supports the following two architectures:
American National Standards Institute (ANSI)
International Telecommunications Union - Technology Sector (ITU-TS)