[ns] [2nd Attempt] Can someone help? Two way communication through base station problem.

[Varrian Hall]

Hi all,
    The problem is explained below, however, to sum it up, network animator
shows proper operation because it uses the trace file info.  This is the
problem, i.e., I need the info/response to go through the base-station to
the wired end's udp agent not to the trace file.  This never happens because
the source packet from the wireless end or mobile node goes to the
CMUTrace::recv() method instead of UDP::recv().  Basically any packet I send
from the wireless end, never reaches the other end's agent() which would
then pass it up to the application layer.

please help...

On 6/26/06, Varrian Hall <cystar123 at gmail.com> wrote:
>
> Hello,
>     My scenario is similar to wireless2.tcl where a wired node
> communicates to wireless nodes via a base station(BS).  I'm using a UDPmm
> agent, a slightly modified udp for multimedia, that's attached to both
> source(wired node) and destination(wireless node).  The problem is when (1)
> sending back an ack or (2) sending a source packet originating from wireless
> end, it never makes it back to the wired end through the base-station(BS)
> when tracing through the agent code upd-mm.cc.  Wired end UDPmm::sendmsg
> sends, wireless end UDPmm:recv receives the msg then sends back an ack via
> target_->recv; however target_-> recv is CMUTrace::recv instead of the wired
> end UDPmm::recv.  Since the information I need in the ack or other pkt
> originating from the mobile node, never comes back to wired node's
> UDPmm::recv, I can't accomplish my goal of optimal bandwidth utilization
> using the application code referenced in UDPmm::recv by app_->recv_msg which
> would be MmApp::recv_msg or MmCache::recv_msg.  This same outcome occurs
> when the source packet starts at the wireless end:  the trace file(via
> CMUTrace::recv) shows its arrival, however, UDPmm::recv never gets the
> packet via the BS.
>     The key observation is packets going through the BS from the wireless
> end never make it to the other end's agent(UDPmm::recv), instead it's
> implied in the trace file.  Does someone know how to reroute this so that my
> application can get the response via it's agent.
>
>
> thanks,
>

-- 
Varrian Hall
MS Graduate Student
Computer Science
Texas A&M University
College Station, TX