3Com T1/PRI manual This diagram represents this process

Configuring Span Lines 1 and 2 2-3

This diagram represents this process.

Encoded HDB3 Signal

Bit Stream

Framer Circuitry

Line Interface Unit

Transformer

Configure the NAC framer to respond or ignore the loop-up/loop-down pattern from the Telco.

Menu Option 4 Configuring the span line’s jitter attenuation

Jitter attenuation on the span line enhances the network interface card (NIC) tolerance to jitter. The NIC’s hardware provides a 193-bit frame buffer to compensate for low frequency jitter on the network.

This option allows you to attenuate jitter on the receiving (from switch to you) and the transmitting (from you to switch) sides. It defaults to the attenuate jitter on the transmitting side.

If you are using the Dual Channelized T1 (386) NAC with a Short Haul (DSX-1) NIC, jitter attenuation is only allowed on the receiving side.

Menu Option 5 Configuring the span line’s transmit line build out

The span line’s transmit line build out is a configurable output attenuation that can be set to satisfy T1 circuit requirements.