Subject: [manet] TCP, multi-hop MANETS and timeouts?

From: Claudio Lavecchia <[email-masked]>
Date: Fri, 24 Jun 2005 13:06:44 +0200

Hello everybody,

I am doing some practical experiences on multi-hop MANETs. I have some 
results that I cannot explain and I would like to have your opinion on this.

I have a two-hops network (besed on off the shelf 802.11) that has the 
following topology:

A----B----C

Node C initiates a two-hops FTP connection to node A.
I have a graphical interface for the FTP server at node A that allows me 
to monitor incoming connections. Through this interface I have set the 
following parameters on FTP server on node A:

Connection timeout: NO TIMEOUT
No Tranfer timeout: NO TIMEOUT
Login timeout:          NO TIMEOUT

I set those parameters to make sure that the FTP connection does not 
close due to weird things happenning on TCP timeouts on multi-hop FTP 
connection. If I understand correctly, this means that there are no 
timeouts at FTP server side.

Now what I experience is that the FTP transfer sometimes stalls anyway, 
it starts by transferring some packets and then it stops. The network 
connectivity is always up and running.
I would say that there are timeouts somewhere that make the FTP 
connection stall. Does anyone has any idea on what could cause this 
behavior?

Thanks a lot

Claudio

_______________________________________________
manet mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/manet

---

From: "Mullen, John" <[email-masked]>
Date: Fri, 24 Jun 2005 09:01:33 -0600

Hi Claduio,

Certain operations will wait until a particular type of control packet
is received before continuing.  However, from time to time, control
packets are lost.  What the timeouts do is limit the amount of time the
process will wait before assuming the packet is lost and moving on.  By
eliminating the timeouts, you have set up a situation in which the
process will wait forever for a packet that will never arrive. 

John P. Mullen, Ph.D.
(505) 646-2958
[email-masked]
 
-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of Claudio Lavecchia
Sent: Friday, June 24, 2005 5:07 AM
To: [email-masked]
Subject: [manet] TCP, multi-hop MANETS and timeouts?

Hello everybody,

I am doing some practical experiences on multi-hop MANETs. I have some
results that I cannot explain and I would like to have your opinion on
this.

A----B----C

Thanks a lot

Claudio