[Spread-users] Many packet retransmited in WAN

John Schultz jschultz at spreadconcepts.com
Tue Jun 13 16:49:31 EDT 2006

Stanisław Trytek wrote:

> Interesting thing is
> that the daemon B receives and delivers the first message and ask the  
> daemon A to retransmit next 9 packets. Next, having again token, 
> daemon B  delivers the second message and asks about 8, and so on ...

It seems like one or more of the routers is delaying the data packets 
from daemon A. 

In your log files you can see that daemon B is getting one of the data 
packets per round for a while but then it gets a ton of late retransmits 
of the same packets.  For some reason, it seems that your data packets 
are getting delayed while your token packets are actually making it 
through as normal. 

When a daemon has the token it sends its data messages and then it sends 
the token.  Data and token traffic occur on two seperate ports.  It is 
generally assumed that if the packets are not dropped along the way, 
then the data packets will generally arrive before the token packet.  
For some reason this general assumption seems to be *grossly* wrong for 
your environment.  It might be that your routers are being "smart" and 
deciding that too much traffic is occurring on the data channel port and 
therefore giving priority to the token channel port traffic.  As you can 
see, this can cause major problems for the ring protocol in such a small 

> Why daemon B delivers only one message per token round? Is it desired  
> behaviour?
> Is it possible to force spread to deliver more than one message per 
> token  round?

No, this is *not* desired behavior and is almost certainly an artifact 
of something strange either in your network or your machines, as we've 
had plenty of WAN deployments that worked fine in the past.

John Schultz
Spread Concepts LLC
Phn:  301 498 3233
Cell: 443 838 2200

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