Riverstone Networks RS Switch Router User Guide Release 8.0 30-31
WAN Configuration Channelized T1, E1 and T3 Services Overview
Warning Hot swapping WICs is not yet supported.
30.16.2 Channelized T3 Service Interface Module
The Channelized T3 (CT3) service interface module on the RS 32000 and RS 38000 comprises four ports, with each
port connection having a separate BNC connector Transmit/Receive pair. The module has an internal DSU, and each
CT3 port has an associated RJ-48c T1 test port. The CT3 service interface module for the RS 8000 and 8600 has two
ports, but has no test ports.
A total of 28 DS1 channels are available for the serial transmission of data. Each DS1 channel can be configured to
use a portion of the DS1 bandwidth or the entire DS1 bandwidth for data transmission. Bandwidth for each DS1
channel can be configured for n x 56 kbps or n x 64 kbps (where n is 1 to 24). The unused portion of the T1 bandwidth,
when not running at full T1 speed, is filled with idle-channel data.
The CT3 service module provides bandwidth aggregation functionality via the standards based Multilink PPP.
Framing and line coding schemes are employed to ensure the reliable transmission of the data; the schemes used
depend on the interface, as shown in Table 3 0-3.
Table 30-2 T1 and E1 Framing and Line Coding Schemes
Interface Framing Line Coding
T1 Extended Superframe Format (ESF)
Superframe — D4 Framing
(SF)
Japanese variants of these formats are also
supported:
S 'FB)
'FB)
Bipolar 8 zero substitution (B8ZS)
Alternate Mark Inversion (AMI)
E1 CRC4, cyclic redundancy check 4
NOCRC4, International (Si)
Bits used
High-density bipolar 3 (HDB3)
Alternate Mark Inversion (AMI)
Table 30-3 Channelized DS3 Framing and Line Coding Schemes
Interface Framing Line Coding
DS3 C-bit Framing
M23 Framing
Bipolar 3 zero substitution (B3ZS)