Serial Port Dynamic DTE Clock speeds ?

[scotys]

Hi,
I need to confirm that for a 2600 with a WIC-2T when set in DTE mode that it will follow the clock presented to it over a synchronous X21 connection as the clock varies dynamically ie the link has dynamic bandwidth allocation.

Or does the Serial port expect to see the clock rate change in fixed steps? If so what are the increments?

thanks

Simon

 

[Kaja1]

The clock supplied by the DCE equipment will remain a constant. Dynamic bandwidth allocation is done by traffic shaping not by changing the clock speed.
An example will be where you are running a Frame relay circuit. The clockrate may be 2 meg but your confirmed information rate( the guarenteed bandwidth) is only 128 kbps. The peak information rate may be set at 500kbps. These rates are controlled and set by your circuit supplier and agreed by contract.

 

[scotys]

In 90 percent of the world this is correct, but when using an intelligent multiplexer like the Vocality V100, Voice can be given the priority over data and so the clock speed presented to the Cisco will constantly change depending on the bandwidth (data rate) remaining (which depends on the number of voice calls and other data channels).

The Serial port is running HDLC.

cheers
Simon