[ns] queueing mechanism in ns
Fri, 28 Jul 2000 20:37:40 +0530 (IST)
immense thanks for the answer.
On Fri, 28 Jul 2000, Tarik Alj wrote:
> transmission delay is independent of the queueing here. In the trace you show
> the packet arrives at an empty queue, it is immediately served. The transmission
> delay is added after the dequeueing event (between - and r). Please read chapter
> 6 and 8 of the manual.
> >Date: Fri, 28 Jul 2000 12:17:09 +0530 (IST)
> >From: Punyaslok Purkayastha <email@example.com>
> >To: firstname.lastname@example.org
> >cc: email@example.com
> >Subject: [ns] queueing mechanism in ns
> >MIME-Version: 1.0
> >i am not quite sure i understand the exact queueing and delay mechanisms
> >of ns. i am employing a tcp source going through a
> >single link. the first two lines of output in my trace file are
> >+ 0 0 1 tcp 750 ------- 1 0.0 1.0 0 0
> >- 0 0 1 tcp 750 ------- 1 0.0 1.0 0 0
> >now my tcp packets should suffer a transmission delay of .6 ms. however
> >the output shows that the packet suffers no delay at all ( it gets
> >enqueued and dequeued at the same time).
> >however note (at a later portion of the trace file)
> >r 0.0206 0 1 tcp 750 ------- 1 0.0 1.0 0 0
> >the propagation delay of my forward direction link is 20ms; so that i do
> >get that the said tcp packet arrives at the receiving end 20ms+.6ms later.
> >i am perplexed by what is going on.