topic Re: How Pathwork handle delay message in Operating System - OpenVMS

How Pathwork handle delay message

Seng_2 — Mon, 03 Jul 2006 07:20:58 GMT

Hi

I'm using PathWork v 7.1 on Windows XP. I have some questions about how Pathwork will handle out of sequence messages. For example if the receiver (Pathwork) expects messages come in sequence 1 , 2 and 3. However,if a receiver got 2,3 and 1.
I found that PathWork will wait for 1 to come ( wait 3 seconds ). It didnt pass 2 and 3 to upper layer until 1 comes.
I'm wondering whether this is a behavior of Pathwork or not. If this is a correct behavior then would it be possible to reduce a wait time ( 3 secs ).
Thanks in advance.

Regards

Seng

Re: How Pathwork handle delay message

Wim Van den Wyngaert — Mon, 03 Jul 2006 08:02:13 GMT

If it is using decnet :

The effect of delay factor is to increase the
retransmission time by increasing the average round trip delay time, thus allowing for additional network delay.

The value of the weighting factor is given by the delay weight characteristic.
Basically, delay weight determines how quickly the retransmission timer responds to variations in actual round-trip delay times. A low value of delay weight means that the retransmission timer responds quickly to each sample of round-trip delay time; a delay weight of 0 means that an estimate is nearly the same as the last actual sample of round trip delay. A high value for delay weight reduces the impact of recent variations in network delay; the higher the value, the closer each estimate of round trip delay is to the average of all estimates.

If it is using IP :

Retransmission occcurs after 1 sec (tcp_rexmit_interval_min) and the delay is doubled after each retransmission. It may also decide itself to retransmit e.g. when it receives duplicate acks.

Wim

Re: How Pathwork handle delay message

Seng_2 — Mon, 03 Jul 2006 21:17:09 GMT

Thanks very much Wim. I'm using Decnet so I assumed that this waiting behavior is the nature of Pathwork or Decnet for being relaiable.