Method and device for preserving pacing information across a transport medium

A method of preserving data link layer pacing information across a transport medium carrying client data, wherein, prior to transmission over the transport medium, each frame of said client data is encoded with an inter-frame time field indicating the time between the start of a current frame and the end of a preceding frame, said method comprising:

• (a) receiving serial data into a deframer at a destination site connected to said transport medium;
• (b) converting said serial data to parallel data;
• (c) removing any framing associated with said transport medium;
• (d) decoding said parallel data at a de-mapper and placing said parallel data in a transmit buffer;
• (e) incrementing a transmitter idle counter;
• (f) detecting a frame in a transmit buffer with a transmit controller;
• (g) extracting a start of frame delimiter field and said inter-frame time field from said detected frame;
• (h) comparing an inter-frame time represented by said incrementing transmitter idle counter to said inter-frame time field;
• (i) if the time count captured in said transmitter idle counter is greater than or equal to the encoded time contained in said inter-frame time field, feeding said frame to a serializer and removing an end of frame delimiter;
• and
• (j) serializing said frame and sending said frame to a client,
• wherein said client data is associated with a first protocol format and is transmitted at a first data rate;
• and wherein said transport medium is associated with a second protocol format and operates at a second data rate.

A method of managing the communication between originating and destination entities connected to a transport medium, comprising the steps of:

• (a) generating a frame containing a value representing the time between the end of a preceding frame and the start of a current frame of a client protocol;
• (b) transmitting the generated frame from the originating entity;
• (c) receiving the generated frame at the destination entity;
• and
• (d) handling the received frame in conjunction with the inter-frame timing information.

A method of preserving data link layer pacing information across a transport medium comprising:

• (a) receiving serial data at a deserializer from a client in a first protocol format at a first rate;
• (b) recovering a clock signal from said received serial data;
• (c) converting said received serial data to parallel data and inputting said parallel data to a FIFO queue;
• (d) detecting the end of a preceding client frame at a receive controller and clearing an inter-frame time counter having an associated count;
• (e) incrementing said inter-frame time counter until the start of a current client frame is received;
• (f) detecting the start of said current client frame;
• (g) inserting in the preceding client frame a start of frame delimiter followed by the associated count of said incremented inter-frame counter;
• (h) sending said preceding client frame to a receive buffer;
• (i) inserting an end of frame delimiter when the end of said preceding frame is detected;
• (j) extracting said preceding client frame from said receive buffer to a mapper;
• and
• (k) mapping said preceding client frame into a protocol format associated with said transport medium, and serializing said mapped frame for transmission across said transport medium at a second data rate.