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BraCa's questions

Martin Hope
BraCa
Asked: 2011-10-17 14:35:17 +0800 CST
  • 1

I've been reading some stuff SIP related, and I'm confused, about what is a SIP back-to-back user agent(B2BUA) and a 'normal' user agent?

Can anyone explain the differences?

From what I read I can't differentiate a B2BUA from a UA... For me a UA acts as a UAS (User Agent Server) when needs to answer a request, and as a UAC (User Agent Client) when needs to send a request..

But I can't understand how different a B2BUA is..

Sorry if this doesnt make sense, but I'm a little bit confused

sip useragent
Martin Hope
BraCa
Asked: 2011-10-09 04:32:02 +0800 CST
  • 2

I have access to a cluster that uses 'torque' (I think) and we use PBS scripts to submit jobs. I need to run more then 200 instances of an app that I've developed in java. The app acts as a peer forming a P2P network, which means that those instances communicate with each other through sockets.

I was able to do my tests with 100 instances running on a single node on the cluster, but when running 200 instances on a single node it doesn't work, and I can't ask for more resources (mem, cores, etc.)

My question is: should I do this the way I'm doing it? With a serial script in which I start all my instances one by one sending them to the background and then wait for them?

Could this be accomplished with a parallel script in which I could ask for 2 nodes and instantiate 100 instances of my app in each node? In this case, I have some other questions: How can I do it? and is there any guarantee that both jobs run at the same time? All 200 instances must be running at the same time.

  • To form the P2P network at least one peer IP address must be known in a serial job, I can get the node IP address in the script and pass it as a parameter to the app, but in a parallel job with 2 nodes how can I do this?

This is part of the script that I'm currently using...

#PBS -l nodes=1:ppn=4
#PBS -l pmem=6GB
#PBS -l walltime=00:20:00
IP=`/sbin/ifconfig eth0 | grep 'inet ' | awk '{print $2}' | sed 's/addr://'`
PORT_PEER=3000
java -jar $JAR $JAR_PARAMS -ip=$IP -port=$PORT_PEER & # first peer, others connect to this one..
  for i in {1..99}
  do
   PORT_PEER=`expr $PORT_PEER + 2`;
   java -jar $JAR $JAR_PARAMS -ip=$IP -port=$PORT_PEER -bootstrap=$IP:3000 &
   sleep 1s
  done
 wait # wait here until all instances terminates
linux cluster pbs