2007/01/031 Bandwidth Test Controller Speaker ： Po-Chou Chen Cheng-Lin Tsai Advisor ： Quincy Wu Date ： 2008/01/03

2007/01/032 Outline Introduction Bwctl install Iperf Client & Daemon Demo Reference

2007/01/033 Introduction Bandwidth Test Controller (BWCTL) BWCTL was developed for use with E2E piPEs ( End-to-End Performance Initiative Performance Environment System ) and Abilene Measurement Infrastructure Motivation Iperf is one of the tools for throughput tests The major objective for the BWCTL was to create a resource allocation and scheduling daemon

2007/01/034 Introduction (Cont.) Benefits Run Iperf tool on two endpoints and hosts on intermediate paths before the development of BWCTL It allows authorized testers to request and run tests without hands on support from NOC staff

2007/01/035 Introduction (Cont.) BWCTL wraps Iperf by actually executing the Iperf command line program on the system BWCTL will work as a 3-party application. The client can arrange a test between two servers on two different systems

2007/01/036 Bwctl install Iperf version 2.0 NTP (ntpd) synchronized clock on the local system NTP system calls % tar –zxvf bwctl-$VERS.tar.gz % cd bwctl-$VERS %./configure --prefix=/ami # --prefix is only needed if you don't like the default # (/usr/local on most systems) % make % make install

2007/01/037 Bwctl install(Cont.) TCP/8423 Control communication – client to server TCP/ephemeral Control communication – server to server: Specific range settable using peer ports in bwctld.conf TCP/5001 Iperf testing port – Settable to a range using test ports in bwctld.conf UDP/5001 Iperf testing port – Settable to a range using test ports in bwctld.conf)

2007/01/038 Iperf Iperf is a tool to measure maximum TCP bandwidth, allowing the tuning of various parameters and UDP characteristics. Iperf reports bandwidth, delay jitter, datagram loss. Server side: $ iperf -s $ iperf -s -D (run the server as a daemon) $ iperf -s -R (remove the iperf service) Client side: $ iperf -c remohost

2007/01/039 Iperf (cont.) Client and Server Options -f [k|m|K|M ]:A letter specifying the format to print bandwidth numbers in. 'b' = bits/sec 'B' = Bytes/sec 'k' = Kbits/sec 'K' = KBytes/sec 'm' = Mbits/sec 'M' = MBytes/sec 'g' = Gbits/sec 'G' = GBytes/sec -i : Sets the interval time in seconds between periodic bandwidth -u: Use UDP rather than TCP -w: For TCP, this sets the TCP window size. For UDP, it is just the buffer which datagrams are received in

2007/01/0310 Iperf (cont.) Client Options -t : The time in seconds to transmit for (Default is 10 seconds ) -b: The UDP bandwidth to send at, in bits/sec. (Default is 1 Mbit/sec.) -n: Sends an array of len bytes num times Bind to an IPv6 address Server side: $ iperf -s -V Client side: $ iperf -c -V

2007/01/0311 bwctl (client) & bwctld (daemon) BWCTL contains two application bwctl (client) bwctld (daemon) bwctl bwctl makes requests to both endpoints of a test If no server is available on the localhost, the client handles the test endpoint.

2007/01/0312 bwctld (Daemon) bwctld bwctld is a traditional accept/fork style daemon The bwctld on each test host: Accepts request “Iperf” tests including time slot and parameters for test Responds with a tentative reservation or a denied message Brokers resources Runs tests Returns results to both sides of the test

2007/01/0313 Control Flow for BWCTL Architecture (General Case)

2007/01/0314 Local bwctld not available

2007/01/0315 Bwctld.conf var_dir vardir Directory path where the bwctld.pid file will be placed. user user Specifies the uid the bwctld process should run as. user can be specified using a valid user name on the system or by using -uid. This option is only used if bwctld is started as root. If the given user has root permissions, the root_folly option must also be specified. group group Specifies the gid the bwctld process should run as. group can be specified using a valid group name on the system or by using -gid. This option is only used if bwctld is started as root.

2007/01/0316 Bwctld.limits Hierarchical Limitclasses

2007/01/0317 Bwctld.limits (Cont.) Available per limitclass Root: Complete set of resources available Hostile: No tests allowed NOC: Inherit Root limits Peer: Limit UDP to 500m Could make children limitclasses for each individual peer if lower limits should be applied to some Normal: UDP not needed for most end users Open: No tests allowed

2007/01/0318 Bwctld.limits (Cont.) IP/netmask Assign net ::1/127 ami assign net /16 ami assign net /32 ami Username and AES key assign user mac ami

2007/01/0319 Bwctld.keys /ami/bin/aespasswd Used to create and manage an AES keyfile. SYNOPSIS aespasswd [-n] [-d] -f keyfile identity OPTIONS -n Create the keyfile -d Delete given identity from keyfile -f keyfile Specifies file that holds identity/key pairs

2007/01/0320 Running Bandwidth Test Controller Testing the bwctl Client /ami/bin/bwctl –c create a test toward /ami/bin/bwctl –s create a test from /ami/bin/bwctl -A AE aeskey mac –c -s Testing the bwctld with debug mode /ami/bin/bwctld -Z

2007/01/0321 Reference Internet2 Iperf