Re: [ns] Packet format

[Tarik Alj <aljtarik@inrs-telecom.uquebec.ca>]

On Fri, 22 Sep 2000, Laurent Silvio Ciavaglia wrote:

> Hello ns users,
> 
> I would like to know if it is possible to change the format of packet
> within a queue.
> e.g.
> incoming format packet X ----> queue + processing ----> outgoing format
> packet Y

what exactly would mean by format, is it the size of the packet for
example (e.g. fragment it) or do you just wish to modify information
contained in headers?

modifying info in the headers should not be hard, you could use a filter
object before or after the queue, so you would not have to do it inside
the queue, unless that's absolutely necessary.

if you need to allocate packets, then a look at agent.h and agent.cc would
probably give you some insight. 

By default all headers are present and accessible for a packet, it's up
to the users to choose wether or not to make use of them; you can also get
rid of the unwanted ones. 

 > 
> My problem is : do I need to make the entry of the queue the endpoint of
> incoming packets and "create" new outgoing packets going to the final
> destination or can I just specify to change the format, and how can ns
> react in terms of event scheduling for the simulations (packets are
> associated to events, no ?)
> 
> Any help will be greatly appreciated.
> Thanks in advance, Laurent Ciavaglia
>