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Re: [ns] the direction field in packet header hdr_cmn
>Date: Mon, 19 Jun 2000 13:54:24 -0700 (PDT)
>From: Yan Yu <[email protected]>
>To: Tarik Alj <[email protected]>
>cc: ns-users <[email protected]>
>Subject: Re: [ns] the direction field in packet header hdr_cmn
>MIME-Version: 1.0
>
>HI, thanks for your hint. I found the direction field is overwritten to
>NONE, why??
it's a reset, I guess to make it cleaner. It has the same effect as reversing
the direction field, and prevent packets from looping.
>also, does the NetworkInterface is used by any network layer protocol?
all of them? it's a network interface...
>
>Thanks a LOT,
>yan
>
>On Mon, 19 Jun 2000, Tarik Alj wrote:
>
>> 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 <[email protected]>
>> >To: ns-users <[email protected]>
>> >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
>>
>
Tarik