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[Xen-devel] Query about how TCP transmission is handled in Xen 3.0 Guest

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Subject: [Xen-devel] Query about how TCP transmission is handled in Xen 3.0 Guest
From: Arjun <cse.syslab@xxxxxxxxx>
Date: Wed, 5 Apr 2006 01:49:04 -0400
Delivery-date: Tue, 04 Apr 2006 22:49:24 -0700
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I have a question regarding TCP transmissions from a Xen guest.

I'm using a simple Java send client, that sends a fixed size message to an external host via Java TCP socket library.
My question is, when my send() function returns, does it mean that :

a) The TCP message has been sent and the acknowlegement received from the receiver side, then the send() function returns.


b) The TCP message has only been put into the network transmit ring (to be handled by Dom0 at a later point of time) and the
send() function returns.

I read the latest Interface manual available from http://www.cl.cam.ac.uk/Research/SRG/netos/xen/readmes/interface/interface.html .
Section 8.1.2 and its not clear to me what exactly happens here.

What I want to ask is, does my high-level Java function, wait till the Guest TCP layer receives acknowledgements for all packets transmitted (for 1 send)
before returning ?

Thanks in advance

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