4-4DCP Mode 1 Networks — 56 Kbps

________________________________________________________________________________________________

________________________________________________________________________________________________

Static Access

Static SDDN (non-ISDN) allows customers currently subscribing to SDN voice applications to transmit data on the same access arrangement by designating a subgroup defined for data terminations. Customers using this configuration must have a trunk subgroup (TSG) dedicated to SDDN 56 Kbps between the customer premises and a central office. They must also have a System 75 R1V3 Issue 2.1 or later, a System 85 R2V3 or R2V4, or a DEFINITY Generic 1, Generic 2, or Generic 3 switch.

The central office must provide one of the following:

SDN, T1.5, or DDS and Switched Digital Service (SDS), or compatible service offered by another vendor

A 4ESS supporting 56 Kbps service

A customer with T1.5 access to a central office tariffed for SDN and T1.5 that does not home to a 4ESS with SDS cannot use this option.

Dynamic Access

Dynamic SDDN (non-ISDN) allows customers that currently subscribe to SDN voice applications to transmit data on the same access arrangement by prefixing a 115 feature code in front of a telephone number. This allows customers to alternately transmit voice and data on one access line; a separate trunk group for 56 Kbps data is not required.

The T1.5 is dedicated to SDN and is therefore not exclusively 56 Kbps. The central office must route to a 4ESS that supports 56 Kbps via digital connectivity. This access may only be offered on circuits without echo cancellation.

The dynamic arrangement is not possible from locations using DDS access. DDS lines must terminate in a central office that has been tariffed for SDN, DDS, and SDS.

System 85 R2V3 and R2V4 do not support dynamic access. System 75 R1V3 and and DEFINITY Generic 1, Generic 2, and Generic 3 do support dynamic access. However, if a customer wants to use a Generic 2 for Switched 56 Kbps networking, contact the BCSDC for help.

NOTE

Dynamic trunk group arrangements cannot be used by modem pooling. If a customer has both 56 Kbps and modem pooling, two trunk groups are required.

Page 50
Image 50
AT&T 585-300-903 manual Static Access, Dynamic Access, 4DCP Mode 1 Networks 56 Kbps