Service providers can cut
costs with SS7oIP by offloading data
traffic from SS7 networks onto IP networks. For example, Short Message
Service (SMS) data is saturating GSM service providers' SS7 networks.
SS7 Over IP enables wireless service providers to rapidly deploy
emerging IP-based services for the mobile Internet that freely interact
with the legacy mobile infrastructure.
SIGTRAN is the name given
to an IETF working group that produced specifications for a family of
protocols that provide reliable datagram service and user layer
adaptations for SS7 and ISDN communications protocols . The most
significant protocol defined by the SIGTRAN group was the Stream
Control Transmission Protocol ( SCTP ) which uses the Internet Protocol
(IP) as its network protocol.
SCTP is a reliable
transport protocol operating on top of a potentially unreliable
connectionless packet service such as IP. It offers acknowledged
error-free non-duplicated transfer of datagrams (messages). Detection
of data corruption, loss of data and duplication of data is achieved by
using checksums and sequence numbers. A selective retransmission
mechanism is applied to correct loss or corruption of data.
Benefits:
-
Ease of
deployment: When using signaling gateways (such as
access service group [ASG]), there is no need to disrupt the existing
SS7 network, and future enhancements are transparent.
-
Less
costly equipment: There is no need for further expensive
investments in the legacy signaling elements.
-
Better
efficiency: SIGTRAN over an IP network doesn't require
the physical E1/T1 over synchronous digital hierarchy (SDH) rings.
Using new technologies like IP over SDH and IP over fiber, for
instance, can achieve much higher throughput.
-
Higher
bandwidth: SIGTRAN information over IP does not
constrain to link capacity as it does in the SS7 network. The IP
network is much more flexible than the TDM-based legacy network.
-
Enhanced
services: Implementing a core IP network facilitates a
variety of new solutions and value-added services (VAS).
RFCs
-
RFC
3286 -- An Introduction to the Stream Control Transmission
Protocol
-
RFC
3257 -- Stream Control Transmission Protocol Applicability
Statement
-
RFC
2960 -- Stream Control Transmission Protocol
-
RFC
3873 --Stream Control Transmission Protocol (SCTP) Management
Information Base (MIB)
-
RFC
3758 -- Stream Control Transmission Protocol (SCTP) Partial
Reliability Extension
-
RFC
3436 -- Transport Layer Security over Stream Control
Transmission Protocol
SS7oIP /
SIGTRAN Resources:
IEC SIGTRAN Tutorial
IETF SIGTRAN Charter
IEC
SCTP Tutorial
SCTP for beginners
Opensource
SIGTRAN project
www.sigtran.org
Linux
Kernel SCTP Project
SS7 Over IP
Comments
SMS layers in ITU SIGTRAN
What are the layers involved in Sigtran for SMS?
balajikishore