Using HDLC.FRAME Protocol

Request Specific Processing

Request Specific Processing

Control Requests

All control writes to this protocol share a common format. The first four bytes are defined as a header

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1

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Control Code

 

 

 

 

 

 

 

 

Control Length

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Packet Length(0)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Control Code

 

Defines the action to be taken by this request.

 

 

 

 

 

 

Control Length

The byte length of the data for this control request.

 

 

 

 

 

 

 

 

 

 

This data immediately follows the header.

 

 

 

 

 

 

 

 

Packet Length

 

Some protocols allow packet data (data to be

 

 

 

 

 

 

 

 

 

 

 

 

 

transmitted over the wire) to be passed to a control

 

 

 

 

 

 

 

 

 

 

write following the control request data. For this

 

 

 

 

 

 

 

 

 

 

 

protocol, these two bytes must be zero because the

 

 

 

 

 

 

 

 

 

 

 

protocol does not allow packet data within a control

 

 

 

 

 

 

 

 

 

 

write.

 

 

 

 

 

 

 

 

 

 

This protocol supports the following Control Code:

5 CW_STATS

Send IO_STATS status message

 

This control write triggers the protocol to send an

 

IO_STATS status message. For the format of this

 

message, see the section on “Status and Error

 

Messages”. The control length is zero.

Note that the Non-E1/T1 version of this protocol must have Control Write processing enabled, in order to be able to process Control Write requests. See the “Terminal Definitions” section of Chapter 4 , “Protocol Specific Configuration,” for details.

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Chapter 3