Avaya 555-245-600 manual Signaling resources

Resource sizing

Signaling resources

The TN799DP C-LAN and the TN2312BP (IPSI) circuit packs are the primary signaling traffic bearing components residing within a port network. Both have finite internal resources such as sockets and data-link connection identifiers (DLCIs) for assignment to and use by endpoints. In addition, both components, being circuit packs, have firmware running on processors with finite capacities to process signaling traffic. Therefore resource sizing the IPSI and the C-LAN involves both tracking the sockets/DLCIs and the signaling traffic throughput.

The TN799DP C-LAN circuit pack provides the interface for a signaling channel between an IP endpoint and a packet bus (which ultimately interfaces with the Avaya server). When an IP endpoint, G250 MG, G350 MG, or G700 MG registers to a C-LAN circuit pack, it allocates a TCP socket dedicated to that endpoint or gateway, for as long as it remains registered. C-LAN sockets are also required for the support of certain adjuncts.

Each C-LAN circuit pack has a finite number of C-LAN sockets. The total number of C-LAN circuit packs that are required to support a particular system depends on the total required number of C-LAN sockets, which in turn depends on the total number of IP endpoints, G250/ G350/G700 MGs, and adjuncts. An individual C-LAN circuit pack can support endpoints in different Network Regions, even those that are not administered to communicate with each other.

Sizing the TN2312BP IPSI circuit packs is a fairly straightforward process. The number of IPSI circuit packs that are required in the system depends on the total number of C-LAN sockets that are required, and the number of ISDN D-channels in the system. Specifically, each IPSI circuit pack supports up to a combined total of 2,480 C-LAN sockets and ISDN D-channels. This is a system-wide constraint, as opposed to a site-by-site constraint. For an IP-PNC system, each PN must house exactly one IPSI circuit pack, neglecting duplicated IPSI circuit packs for enhanced reliability. Therefore, if the C-LAN sockets and the ISDN D-channels indicate a need for more IPSI circuit packs than the required number of PNs to support the TDM usage, more PNs are needed (note that placing two active IPSI circuit packs in a single PN is not permitted). In other words, the number of PNs must be large enough to fulfill both the TDM and the IPSI requirements.

In a system utilizing a circuit-switched center stage an IPSI circuit pack is not required in each port network. However, there are restrictions pertaining to how many port networks can be supported by a single IPSI circuit pack.

If the number of port networks needs to be increased to satisfy the IPSI requirements, then the TDM and media processing engineering processes must be redone (since an increased number of port networks implies an increase in inter-port-network traffic). This is an iterative process.

In addition to counting sockets and DLCIs in allocating C-LANs and IPSIs, a separate, independent traffic engineering process involves modeling the signaling message traffic through them. The rate of message traffic depends primarily on the call traffic at the endpoints and MGs signaling through the sockets/DLCIs. Each call generates a certain amount of messages between the endpoints and the server. The exact number and sizes of the messages depends on the protocols involved. Combining the messages per call with a call rate gives estimates of

Issue 6 January 2008 199