Configuring the sliding window size on a PRI interface
Frames in the Q.921 buffer are sent in sequence. Usually, a frame can be sent only when the last frame is acknowledged. To improve transmission efficiency, the sliding window mechanism is introduced. It allows the system to send multiple continuous frames without having to wait for the acknowledgement to the last frame. The sliding window size determines the maximum number of unacknowledged frames. When sending a frame, the system checks the number of unacknowledged frames. Suppose V(A) is the sequence number of the last acknowledged frame, V(S) is the sequence number of the frame to be sent, and K is the sliding window size. If V(A) + K = V(S), the system stops sending frames.
By default, the sliding window size of an ISDN PRI interface is 7. You can tune the size depending on the link status to maximize the throughput.
To configure the size of the sliding window on a PRI interface:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter interface view. | interface interface-type interface-number | N/A |
3. Configure the sliding window size on the PRI interface. | isdn pri-slipwnd-size window-size | Optional. The sliding window on the PRI interface defaults to 7. |