[ns] Fwd: What is a good resource to study telecommunication basics
Hi, At first, I'd like to say thanks to all those who supplied me with good resources to learn more about computer networking and telecommunications. I thought that sharing the answers might help others who have the same question, so I'm going to give a brief list of resources which one can use to learn more about some of the most important factors in network communications. [1] Computer Networks 4th Ed by Andrew S. Tanenbaum , [Chapter 5, Section 5.4 Quality of Service] : I didn't read the whole book and you may find other sections more useful, but this part of the book gave me a view of what should I look for to get more information.Actually it gave me a lot of good keywords to search for. [2] http://whatis.techtarget.com/ : It's a good IT-specific encyclopedia. bandwidth , latency , and data transfer rate definitions helped me a lot. [3] http://www.spiritus-temporis.com/throughput/the-difference-between-throughput-and-latency.html: A useful web page. [4] http://smutz.us/techtips/NetworkLatency.html : I found it wonderful. After reading these texts I got an overall understanding of the logic behind packet transmission over a link.I think that's enought for a beginner but If you could share more and better resources, I would be happy to read them. Thanks, Mobin -- Forwarded message -- From: Mobin Yazarlou yazarlo...@gmail.com Date: Sat, Sep 11, 2010 at 9:54 AM Subject: What is a good resource to study telecommunication basics To: ns-users@isi.edu Hi, Today I've installed ns-allinone-2.34 package on Linux and tried to start learning NS but after a couple of hours I found that it needs a good understanding of telecommunication basic concepts.Unfortunately my knowledge, as a software engineer, about Networking is limited to application level network programming, application level protocols like HTTP and some other protocols like TCP/IP, UDP so I need a good resource to study the relation between Bandwidth, Link delay, packet size and packet rate which are essential for anyone who wants to simulate a network with NS. Could you share the resources by which you learned these topics with me? Thanks in advance, Mobin
[ns] RREQ in aodv
Hello
To discard the RREQ in aodv.cc file if a condition is satisfied, I try this
part in aodv.cc, but I don't know the technique to achieve it, please can you
help me?
/*
* Can't reply. So forward the Route Request
*/
else {
if(mycondition()){
ih-saddr() = index;
ih-daddr() = IP_BROADCAST;
rq-rq_hop_count += 1;
// Maximum sequence number seen en route
if (rt) rq-rq_dst_seqno = max(rt-rt_seqno, rq-rq_dst_seqno);
forward((aodv_rt_entry*) 0, p, DELAY);
}
else {
printf(%d No cas \n, index);
Packet::free(p);
}
}
}
All the best
Lyx
[ns] ParePool/ProxyTrace Server Problem and effect on Average Client Latency
Here is my topology below:
Clients Single Web Cache Outer Router Servers
CCCE===OSSS
100mbps 1ms 10 mbps 100 ms 100mbps 1ms
*All links are duplex.
I have 72 client computers (CCC) connected to a single cache server (E)
for { set i 0} { $i 72 } { incr i }{
$client($i) connect $cache
}
I also connect the cache (C) to N servers (SSS)
for { set i 0} { $i $N } { incr i }{
$cache connect $server($i)
}
and start each client to connect to all N servers using a nested for loop
$client($i) start-connection $cache $server($j)
Then, I use PagePool/ProxyTrace and a proxy trace file to simulate actual
request from our proxy server. I also defined client num as 72, but there is no
way to define how many servers are needed.
The problem is that in my simulation, the more servers I add, the lesser the
average latency of the client request. It seems there is a bottleneck somewhere
in the simulation that I can't seem to find. The 10 mbps link is not congested
so the bottleneck is not in the network topology. I looked at the source code
for the HTTP/Cient , Http/Server and HTTP/Cache and it does not limit the
number of connections per server per client.
Here is a table regarding the average latency during a 1 hour test period with
varying number of Servers.
Servers Ave. LatencyMax Latency Size of max latency
1 44.273616178936 194.75787848001 63958 bytes
2 19.054615947881 76.160913280016 27259 bytes
3 6.8249151116920 43.515350479991 1958 bytes
5 2.6904748712405 40.750138319997 2026007 bytes
10 1.4624603352714 41.162682479988 2026007 bytes
25 1.1519090774774 40.95198516 2026007 bytes
50 1.0554587133410 41.318702239997 2026007 bytes
72 1.0247390695315 41.328403759997 2026007 bytes
100 0.169117431 41.315464239997 2026007 bytes
500 0.9304826117915 41.332590639997 2026007 bytes
10000.9044198998673 39.927294799988 2026007 bytes
Is there a limit to the number of request in a single TCP connection/wrapper
when a client connects to a Server?
How can I simulate N number of servers into a single server node using
Pagepool/ProxyTrace without affecting latency? It is cumbersome and unrealistic
to simulate all Servers in the Internet this way.
Thank you for your time and consideration.
Richard Reyes
Instructor
[ns] Fwd: [Help] About configure snoop protocol in wired-cum-wireless architecture
Dear all, I want to asking how to configure script in ns-2, if we wanna implement's snoop agent at link layer in ns-2's wireless network, because i've always failed, if i implement snoop agent in wireless node that work as base station (the problem is : segmentation fault).. but if i simulate snoop agent just in wired network, it works.. i'm using ns version 2.33 as my simulator and simulate wired-cum-wireless network architecture Thanks for attention..
