1

It’s ALMOST There: An Emotional Timeline of the

Development of SCTP Efficiency Plots

By: Jerry Heinz

2

An Overview of SCTP• acknowledged error-free non-

duplicated transfer of user data• data fragmentation to conform to

discovered path MTU size • sequenced delivery of user

messages within multiple streams, with an option for order-of-arrival delivery of individual user messages

• bundling of multiple user messages into a single SCTP packet

• robust communication associations between two endpoints, each of which may be reachable by more than one transport address

[Stewart, 2000]

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Spring 2000

3

Linking It Up: The Reference Implementation

• The standard gunzip, tar, config, make stuff

• Setuid and chmod for the Daemon• Playing with the app. It can do neat

things like:– sethost– setport– setstrms– send messages

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Sept 2000

4

Adding DingHow it will work (next week):Netlab sends ding:1024:1024:16 -----> WrathWrath sends "ack and shutdown" -----> NetlabWrath shutsdown associationWrath adjusts streams Wrath re-associatesWrath sends a wake up call --------> NetlabNetlab sends GO ---------> WrathWrath sends pkt ---------> NetlabWrath sends pkt ---------> Netlab...Wrath sends pkt ---------> NetlabWrath sends end pkt ---------> NetlabNetlab dumps array to fileFin

It’s ALMOST done now!

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Sept & Oct 2000

5

TCPDump Patch

• Needed to watch the data transfer

• There was nothing to help• NOW THERE IS!

How ‘Bout A Sample Dump?

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Late Oct 2000

6

TCPDump Patch

20:58:00.418077 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: init {tag:786129399 rwnd:32768 opnstrms:1 maxinstrms:2048 initialTSN:901821634} (52)20:58:00.418835 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: init ack {tag:195942760 rwnd:32768 opnstrms:1 maxinstrms:2048 initialTSN:-132378165} (832) [tos 0x2]20:58:00.420776 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: cookie (792) [tos 0x2]20:58:00.421587 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: cookie ack (16) [tos 0x2]

>[jheinz@kubla linux]$ ./sctp_test_appMy port is 1239in to register with deamonGot the response!!!I've initiallized properly!preOpenStrm = 0$>sethost:155.247.170.4host set to 155.247.170.4:0>setport:1072Port set to 1072>assoc>SCTP ASSOCIATION UP

At the console:

The dump:

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Late Oct 2000

7

TCPDump Patch

20:58:03.994788 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: sel ack {rwnd:32768 #desc:0 #dupTSN:0} (52) (DF) [tos 0x2]20:58:04.211823 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: sel ack {rwnd:32768 #desc:0 #dupTSN:0} (28) [tos 0x2]20:58:08.314098 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: data (44) (DF) [tos 0x2]20:58:08.531953 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: sel ack {rwnd:32768 #desc:0 #dupTSN:0} (28) [tos 0x2]20:58:17.125398 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: data (48) (DF) [tos 0x2]20:58:17.342285 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: sel ack {rwnd:32768 #desc:0 #dupTSN:0} (28) [tos 0x2]20:58:19.369384 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: data (32) (DF) [tos 0x2]20:58:19.582374 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: sel ack {rwnd:32768 #desc:0 #dupTSN:0} (28) [tos 0x2]

>hello?Returned 0 from the send>how are you?Returned 0 from the send>is anybody home?Returned 0 from the send>byeReturned 0 from the send

At the console:

The dump:

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Late Oct 2000

8

TCPDump Patch>quitSCTP ASSOCIATION DOWN

At the console:

The dump:20:58:28.092701 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: hb req (36) [tos 0x2]20:58:28.093099 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: hb ack (36) [tos 0x2]20:58:29.030345 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: hb req (36) [tos 0x2]20:58:29.030672 SCTP: netlab.cis.temple.edu.1072 > kubla.cis.temple.edu.1239: hb ack (36) [tos 0x2]20:58:29.030935 SCTP: kubla.cis.temple.edu.1239 > netlab.cis.temple.edu.1072: abort (16) [tos 0x2]

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Late Oct 2000

9

Now… Some Graphs for Flavor

It’s ALMOST There: An Emotional Timeline of the Development of SCTP Efficiency Plots

By: Jerry Heinz

Early Nov 2000