Indicators for streams associated with messages

1. A method comprising:

receiving a request message at a destination node;

determining if the destination node is able to process the request message;

determining, by the destination node, if a stop indicator is set for a stream associated with the request message;

determining, by the destination node, if the request message includes a restart indicator;

clearing the stop indicator for the stream if the request message includes the restart indicator and the destination node is able to process the request message;

sending a response message indicating refusal of the request message if the stop indicator is set and the request message does not include the restart indicator;

sending the response message indicating refusal of the request message if the stop indicator for the stream is set, the request message includes a restart indicator, and the destination node is unable to process the request message; and

sending the response message indicating acceptance of the request message if the request message includes the restart indicator and the destination node is able to process the request message.

2. The method of claim 1 further comprising:

determining if the destination node is able to process the request message; and

sending the response message indicating acceptance of the request message if the stop indicator is not set and destination node is able to process the request message.

3. The method of claim 1 further comprising:

determining if the destination node is able to process the request message;

setting the stop indicator for the stream if the stop indicator is not set and the destination node is not able to process the request message; and

sending the response message indicating refusal of the request message, wherein the response includes a first refused indicator, if the destination node is not able to process the request message.

4. A method comprising:

sending a plurality of request messages, in order, from a source node;

receiving a response message indicating refusal of one of the plurality of request messages;

setting, at the source node, a restart pending indicator for a stream associated with the response message indicating refusal;

discontinuing sending additional request messages for the stream until the restart pending indicator is cleared;

maintaining a data structure at the source node, the data structure including a count of outstanding request messages, wherein the count is incremented upon sending each request message and decremented upon receiving the response message for each request message, the data structure further including a first refused indicator, wherein the first refused indicator identifies a first refused request message, the first refused indicator set based on the response message; and

clearing the restart bending indicator once the count of outstanding request messages reaches zero.

5. The method of claim 4 further comprising:

resending the plurality of request messages in order, starting from the first refused request message, once the restart pending indicator is cleared.

6. The method of claim 5 wherein a first resent request message includes a restart indicator.

7. A device comprising:

a hardware request module to send request messages, in order, over a designated communications channel, wherein request messages sent over the designated communications channel are received in the same order as sent, for data packets associated with a stream of ordered data packets while a restart pending indicator for the stream is cleared, the hardware request module further to maintain a count of request messages for which no response has been received; and

a hardware response module to receive response messages for each of the request messages and to set the restart pending indicator for the stream if any response message indicates a refusal of the request message, the response hardware module further clears the restart pending indictor when the count of request messages indicates responses for all request messages have been received and the request module sends request messages starting from a first refused request message.

8. The device of claim 7 wherein the request module further includes a restart indicator in a first request message sent after the restart pending indicator is cleared.

9. The device of claim 7 wherein the device is an application specific integrated circuit.