Specifications

Configure Half-Duplex and Bisync for Synchronous Serial Port Adapters on Cisco 7200 Series Routers

Configuring Serial Interfaces IC-73

Conﬁgure Half-Duplex and Bisync for Synchronous Serial Port Adapters on

Cisco 7200 Series Routers

The synchronous serial port adapters (PA-8T-V35, PA-8T-X21, PA-8T-232, and PA-4T+) on

Cisco 7200 series routers support half-duplex and binary synchronous communications (Bisync).

Bisync is a character-oriented data-link layer protocol for half-duplex applications. In half-duplex

mode, data is sent one direction at a time. Direction is controlled by handshaking the RST and CTS

control lines. These are described in the following sections:

• Conﬁgure Bisync

• Conﬁgure Half-Duplex Carrier Modes and Timers

For more information about the PA-8T-V35, PA-8T-X21, PA-8T-232, and PA-4T+ synchronous

serial port adapters, refer to the following publications:

• PA-8T-V35 Synchronous Serial Port Adapter Installation and Conﬁguration

• PA-8T-X21 Synchronous Serial Port Adapter Installation and Conﬁguration

• PA-8T-232 Synchronous Serial Port Adapter Installation and Conﬁguration

• PA-4T+ Synchronous Serial Port Adapter Installation and Conﬁguration

Conﬁgure Bisync

To conﬁgure the Bisync feature on the synchronous serial port adapters (PA-8T-V35, PA-8T-X21,

PA-8T-232, and PA-4T+) on Cisco 7200 series routers, refer to the “Block Serial Tunnelling

(BSTUN)” section of the “Conﬁguring Serial Tunnel and Block Serial Tunnel” chapter of the

Bridging and IBM Networking Conﬁguration Guide. All commands listed in the “Block Serial

Tunnelling (BSTUN)” section apply to the synchronous serial port adapters on Cisco 7200 series

routers. Any command syntax that speciﬁes an interface number supports the Cisco 7200 series

slot/port syntax.

Conﬁgure Half-Duplex Carrier Modes and Timers

This section describes how to conﬁgure the synchronous serial port adapters (PA-8T-V35,

PA-8T-X21, PA-8T-232, and PA-4T+) on Cisco 7200 series routers. To conﬁgure the half-duplex

feature on synchronous serial port adapters, perform the tasks described in the following sections,

which appear later in this chapter:

• Understand Half-Duplex DTE and DCE State Machines

• Change between Controlled-Carrier and Constant-Carrier Modes Examples

• Tune Half-Duplex Timers

Conﬁgure Compression Service Adapters on Cisco 7500 Series Routers

The SA-Comp/1 and SA-Comp/4 data compression service adapters (CSAs) are available on

Cisco 7200 series routers and on second-generation Versatile Interface Processors (VIP2s) in

Cisco 7500 series routers. (CSAs require VIP2 model VIP2-40.)

The SA-Comp/1 supports up to 64 WAN interfaces, and the SA-Comp/4 supports up to 256 WAN

interfaces.

On the Cisco 7200 series routers you can optionally specify which CSA the interface uses to perform

hardware compression.