The SIGTRAN Working Group of
the IETF has specified the MTP
Level 2 Peer to Peer Adaptation Layer as its standard protocol to enable SS7 links
to run over IP. The M2PA protocol is the layer between SCTP and MTP Level 3. M2PA
serves several purposes. The first purpose is to provide a mechanism for the transport
of SS7 MTP2 user signaling (e.g., MTP3 messages) over IP using
SCTP. The second purpose is to enable seamless operation between MTP2 user
peers in the SS7 and IP space.
The following diagram is an example of how M2PA may be used in the network.
M2PA allows Telecommunications Equipment Makers (TEMs) to keep their existing network
topology (i.e. SSPs, STPs etc) and use IP to transport their SS7 messages instead
of traditional 64K-based links. All other elements from the classic SS7 network
remain the same except the signaling links are now virtual. M2PA simply changes
the transport to IP. M2PA can be used in the event that classic SS7 network topology
(e.g. point codes, signaling links) needs to be preserved while carrying information
via IP transport. Another benefit of M2PA is that IP-centric elements (SSPs, SCPs)
can communicate directly with each other known as direct peer-to-peer communications.
The signaling stack is depicted below:
Signalware and M2PA
The Signalware SIGTRAN M2PA feature is a software solution that replaces the need
for boards (Network Interface Cards (NIC) are still needed.) While it is required
that an IP stack and the associated hardware is available for M2PA for Signalware
to be functional, the IP stack and hardware is not part of the product; rather it
is assumed that IP NICs will be available as part of the operational platform.
The Signalware SIGTRAN M2PA development kit is composed of three primary components:
SCTP,
M2PA and an enhanced version of Signalware. The SCTP and M2PA components
of M2PA for Signalware are each independent software subsystems that are to be designed,
developed and implemented as part of the M2PA for Signalware product development.
The enhanced Signalware component of M2PA for Signalware is a modified version of
the Signalware product that contains, as a minimum, the functionality associated
with MTP3,
SCCP, TCAP,
ISUP and other upper layer protocols.
Ulticom's M2PA Advantages
M2PA allows TEMs to keep their existing network topology (i.e. SSPs, STPs etc) and
use IP to transport their SS7 messages instead of traditional 64K-based links. M2PA
over SCTP is the choice for deployments that require the replacement of SS7 links
with SS7 over IP but would like to maintain the topology of an SS7 network. All
Signalware application API's are consistent between the Signalware SS7 platform
and the M2PA variant enabling applications already deployed on Signalware SS7 to
be seamlessly migrated to SS7 over IP. With thousands of Signalware SS7 platforms
in current deployment, this offers a tremendous market advantage for systems maintaining
the Signalware industry standard API. This offers two benefits to Signalware customers.
First, by changing the transport of signaling messages to SS7 over IP, carriers
can take advantage of the lower cost associated with IP without reinvesting more
time or money into writing new applications. IP also enables carriers higher capacity
to carry traffic than a dedicated 64K-based link. Greater capacity means greater
opportunity to generate revenue.
Since M2PA is built on Signalware, users also receive
open platform support, fault
resiliency and scalability
as standard features. Signalware SIGTRAN M2PA over SCTP enables application servers
such as MGCS, IP based SCP, and other IP centric elements to be deployed in simplex
or fault resilient configurations employing two or more CEs. While this feature
can be done other ways (i.e. TALI), this non-proprietary method enables the customer
to leverage products from other vendors in their solution.
Advantage Summary
- Replaces physical HDLC SS7 links with virtual IP transport associations
- Maintains deterministic real time qualities demanded in signaling applications
- Eliminates SS7 bandwidth limitations incurred by 64kbps restrictions
- Flexibly provisions links on demand
- Reduces SS7 port requirements at remote signaling point
- Reduces real estate, power, cooling, maintenance, rack space, and capital costs
- Flexibly deploys nodes as required, free from geographic restrictions