AT&T DS1/DMi/ISDN-PRI manual ISDN-PRI PUBLIC-NETWORK Connections

NETWORK CONNECTIONS AND CONFIGURATIONS 2-13

System 85 or Generic 2 ISDN-PRI to Another Vendor’s Digital Switch

When a System 85 or Generic 2 ISDN-PRI connects to another vendor’s customer-premises switch (another vendor’s ISDN-PRI or equivalent), several items should be verified to ensure compatibility. These include the interface electrical characteristics, options, and synchronization capabilities. The following questions should be answered:

●Does the vendor product provide a DSX-1 interface?

●Does the vendor product support at least one each of the line coding, framing, and signaling options provided by System 85 or Generic 2?

●For synchronization purposes, what stratum clock does the vendor switch provide?

●Will the vendor switch act as a timing master or slave its timing to the System 85 or Generic 2?

●Does the vendor switch implement the digital loss plan specified by EIA/PIN-1429?

●Can the vendor switch be administered for either the user side or the network side as required?

Depending on the answers to these questions, basic compatibility can be determined.

ISDN-PRI PUBLIC-NETWORK CONNECTIONS

Public network connections typically involve connecting a System 75, System 85, Generic 1, or Generic 2 to a 4ESS. Refer to System 85 R2V4 to 4ESS Via ISDN PRI Access (555-037-232), DEFINITY Communications System Generic 1.1 to 4ESS Via ISDN PRI Access (555-037-234), and DEFINITY Communications System Generic 2.1 to 4ESS Via ISDN PRI Access (555-037-235) for more detailed information on these connections.

System 85 R2V4, Generic 1, and Generic 2 to a 4ESS

Connections to a 4ESS are called special-access connections. The physical connection is made from customer premises to a 4ESS. Toll calls go directly from the customer premises switch to the AT&T toll network. Network ISDN features and services are available through a 4ESS. The physical connection to a 4ESS toll switch is made (through the DIF frame) to a SM9 circuit pack.

Framing, Signaling, and Line Coding

A 4ESS does not place any restrictions on the framing, signaling, and line-coding options. Any applicable restrictions are related to the application and particular installation.