Re: [ns] the direction field in packet header hdr_cmn

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

The network interface (above LL) is responsibke for reseting the direction 
field:

netif.cc

>Date: Mon, 19 Jun 2000 12:50:57 -0700 (PDT)
>From: Yan Yu <yanyu@catarina.usc.edu>
>To: ns-users <ns-users@isi.edu>
>Subject: [ns] the direction field in packet header hdr_cmn
>MIME-Version: 1.0
>
>HI, there, 
>  by looking up the mac layer code, (like mac.cc, mac-802_3.cc, or
>bi-connector.cc), it seems that the MAC layer judge if it is sending or
>receiving the packet( i.e., if the packet is traveling up or down the
>stack) by looking up the direction field in packet header. but from my
>simulation, it seems like the the direction filed is not set up
>properly. I am using Mac-802_3 as MAC layer, LLSnoop as link layer..
>I am wondering who is responsible for setting up the direction field in
>hdr_cmn? which layer??
>
>I guess, say, if it travels up the stack( receving a packet, physical
>layer is responsible for setting it as UP. and as it travels down, the
>higher layer, e.g., application layer, or network layer is reposbile for
>setting it up as DOWN??
>
>any feedback on this is very appreciated!!
>yan

Tarik