The document discusses the Stream Control Transmission Protocol (SCTP), a transport layer protocol that provides reliable message delivery like TCP but with some improvements. SCTP supports multi-homing where an endpoint can be associated with multiple IP addresses simultaneously. It also supports multi-streaming within a single association to reduce head-of-line blocking. SCTP uses a four-way handshake for connection setup and ensures reliable data transfer using transmission sequence numbers and selective acknowledgements.

1. Stream
Control
Transmission
Protocol
(SCTP)
LAILI
AIDI
Presented
as
part
of
candidacy
at
Employer_X

2. 2
Stream Control Transmission Protocol (SCTP)
Laili
Aidi
–
Candidacy
at
Employer_X
Jakarta,
June
12,
2013
Transport
layer
is
responsible
for
process-­‐to-­‐process
delivery.—the
delivery
of
a
packet,
part
of
a
message,
from
one
process
to
another.
Two
processes
communicate
in
a
client/server
relaKonship.
Data
Delivery:
Transport Layer

3. 3
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
Port Numbers
Laili
Aidi
–
Candidacy
at
Employer_X

4. 4
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
IP Address and Port Numbers
Socket
Address
Laili
Aidi
–
Candidacy
at
Employer_X

5. 5
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
New Transport Protocols

Many
applicaKons
need
reliable
message
delivery
–
use
TCP
stream

TCP
provides
both
strict-­‐ordering
and
reliability
–
many
may
not
need
both

Need
new
protocol
to
reduce
user-­‐perceived
latency
and
improve
throughput
Laili
Aidi
–
Candidacy
at
Employer_X

6. 6
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
What is SCTP

SCTP
is
a
message-­‐oriented,
reliable
protocol
(RFC
2960)

On
top of a connectionless packet network

Perform
beXer
in
the
presence
of
losses:
no
strictly
ordered
delivery

Designed
for
new
Internet
applicaKons:
ISDN
over
IP
(IUA),
SS7
signaling
(M2UA,
M3UA),
Media
gateway
control
(H.248),
IP
Telephony
(H323,
SIP),
etc

MulK-­‐homing
support

MulK-­‐stream
support

Unordered
data
delivery
opKon

Reliable
data
transfer
with
SACK

Flow
Control

CongesKon
control

Message
fragmentaKon

Reliable
data
transfer
with
SACK

Flow
Control

CongesKon
control

Message
fragmentaKon
Laili
Aidi
–
Candidacy
at
Employer_X

7. 7
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
Multi-Homing

Two
fundamental
concepts
in
SCTP:
-­‐
Endpoints
(communicaKng
parKes)
-­‐
AssociaKons
(communicaKon
relaKonships)

SCTP
associaKon
allows
mulKple
IP
addresses
for
each
end
point.

This
can
be
represented
as
a
pair
of
SCTP
endpoints:
-­‐
assoc
=
{
[10.1.61.11
:
2223],
[161.10.8.221,
120.1.1.5
:
80]}
160.15.82.20
161.10.8.221
Laili
Aidi
–
Candidacy
at
Employer_X

8. 8
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
Multi-Streams

SCTP
associaKon
can
involve
mulKple
streams.

Reduces
unnecessary
head-­‐of-­‐line
blocking
Laili
Aidi
–
Candidacy
at
Employer_X

9. 9
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
SCTP Packet
 TCP has segments; SCTP has packets.
 Data chunks are identified by 3items:
- TSN: cumulative number defines the association
- SI: defines the stream
- SSN: defines the chunk in a stream

Control
informaKon
&
data
informaKon
are
carried
in
separate
chunks.
Laili
Aidi
–
Candidacy
at
Employer_X

10. 10
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
SCTP Packet

Control
informaKon
and
data
informaKon
are
carried
in
separate
chunks
Laili
Aidi
–
Candidacy
at
Employer_X

11. 11
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
Handshake

SCTP
uses
a
four-­‐way
handshake
to
set
up
an
associaKon
-­‐
Cookie
to
defense
against
TCP
SYN-­‐
aXack
Laili
Aidi
–
Candidacy
at
Employer_X

12. 12
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
Simple Data Transfer
 Only DATA chunks consume TSNs;
 DATA chunks are the only chunks that are acknowledged.

Acknowledgment
defines
the
cumulaKve
TSN,
 The
TSN
of
the
last
data
chunk
received
in
order.
Laili
Aidi
–
Candidacy
at
Employer_X

13. 13
Stream Control Transmission Protocol (SCTP)
Jakarta,
June
12,
2013
Simple Data Transfer
Associa<on
Termina<on
 Acknowledgment
defines
the
cumulaKve
TSN,

The
TSN
of
the
last
data
chunk
received
in
order.
Laili
Aidi
–
Candidacy
at
Employer_X

14. Thank
You
References:

N.
Gupta,
S.
Kumar,
R.
Rajamani,
“SCTP
v/s
TCP
–
A
Comparison
of
Transport
Protocols
for
Web
Traffic”

Cisco,
“A
detailed
overview
of
the
protocol
and
a
examinaKon
of
the
socket
API”

Forouzan,
“Process-­‐to-­‐Process
Delivery:
UDP,
TCP,
and
SCTP”,
Chapter
16
and
23

Karl-­‐Johan
Grinnemo,
“Advanced
Internetworking,
Transport
Layer"