[ns] URGENT: queues in a simple link

[Daniel H�llisch <dh@danho.org>]

Hi there!
I want to create the following topology:
                <------------------ACK-line--------------------|
(TCPsender)-------------->(multiplexer)------------->(TCPsink)

The line from the MUX-node to the sink-node mimics the buffer of the MUX as
well as the link (in terms of bandwidth and delay) itself.
But the line from the sender-node to the MUX-node as well as the ACK-line
both should NOT have any queue.
Because I don't want to have any drops on those links.
When I set the queue-limit of these links large enough so no drop can occur,
the measurement of the RTTs will be wrong, since TCP assumes all packets
that wait in the queue to already be on their way. This then leads to
cumulative RTT values.

How can I setup a simple link in a way that leaves out the queue?
I already tried "$link add-to-head $link_" so packets should directly be
forwarded to the DelayLink object of the link.
But when I started the simulation the scheduler throwed something like
"invalid UID".

Does anyone know what to do?

Thanks in advance, Daniel.
--
Daniel Hoellisch
Munich University of Technology
Germany