Cisco 4000 Series Integrated Services Router

T1 Network Interface

Transmit bit rate

1.544 Mbps ±50 bps/32 ppm

Receive bit rate

1.544 Mbps ±50 bps/32 ppm

Line code

Alternate mark inversion (AMI) and binary 8-zero substitution (B8ZS)

AMI ones density

Enforced for n x 56-kbps channels

Framing format

D4 (Super Frame [SF]) and Extended Super Frame (ESF)

Output level (line build-out [LBO])

0, -7.5 or -15 dB

Input level

+1 dB0 down to -24 dB0

Data-terminal-equipment (DTE) interface (WIC mode)

Fractional service

DTE interface (VIC mode)

G.704 or structured

Data-communications-equipment (DCE) interface

G.704 or structured