Mid-market to large enterprise
Issue 6 January 2008 85
IP Server Interface (TN2312BP) - The IP Server Interface (IPSI) is the communication
interface between the server and the Media Gateways (port networks). The IPSI is responsible
for gateway control, and for tunneling call control messages back to the S8700.
One IPSI circuit pack is required per IPSI-connected Media Gateway for standard reliability.
Duplicated IPSI circuit packs are required per IPSI-connected Media Gateway for high reliability
and critical reliability.
The IPSI is located in the tone/clock slots, and provides the following functions:
● PKTINT packet bus interface
● Archangel TDM bus interface
● Tone/Clock functionality found on the TN2182B Tone/Clock circuit pack
● Ethernet interface for technician access
● Ethernet interface for connectivity to Services laptop computers
● Maintenance board interface for communication with the EPN maintenance board
Each IPSI typically controls up to five gateways by tunneling control messages over the center
stage (TDM) network to the PNs that do not have IPSIs. For locations with high IP Telephone
traffic, Avaya recommends a greater number of IPSI circuit packs.
An IPSI cannot be placed in:
● A PN that has a Stratum-3 clock interface
● A remote PN that uses a DS1 converter
● A Survivable Remote Expansion Port Network (SREPN)
The IPSI supports the following functions:
● Supports eight global Call Classification ports
● Supports network diagnostic capabilities
● Provides PN clock generation and synchronization for Stratum-4 type II only
● Provides PN tone generation
● Provides distributed PN packet interface
● Supports the download of IPSI firmware
● Provides serial number support for License File feature activation
Control LAN (TN799DP) - The TN799DP Control LAN (C-LAN) circuit pack acts as front-end
processor and concentrator and provides the gateway between the public IP Telephony network
and the S8700-system. All H.323 signaling messages between IP Telephony endpoints and the
S8700-series Servers must pass through the C-LAN. The connectivity path between the IP
endpoint and the server is as follows:
Endpoint ⇔ IP Network ⇔ C-LAN ⇔ PN backplane ⇔ IPSI ⇔ IP network ⇔ S8700
