Cisco ASP Protocol Port Device Address Offset

1.3.6.1.4.1.9.9.55.1.1.1.1.4

Specifies the byte offset within a frame, which contains the device address. This is used when the asynchronous interface is configured to use the async generic protocol handler. Because no knowledge of the protocol is built-in to the IOS, it must be told where the address field lives within the frame. That way IOS can correctly route the frames for this protocol.