Re: M2PA vs M2UA

aditi,

M2UA remotes a traditional SS7 signalling link, often collocated
with an MG.  Its original purpose was to replace expensive graded
facilities for narrow-band SS7 links with more cost-effective IP
inter-networking.  This was primarily focused at SS7 network
interconnects, rather than SS7 network owners.  Real world cases
are typically soft-switches with SS7 ISUP call control that have
M2UA provisioned at the MG and a more centralized MGC that performs
upper layer SS7 network functions.

M2PA provides a new kind of signalling link, replacing expensive
graded facilities deeper into the core network and providing the
ability to replace all or part of the SS7 L1 network with an IP
network.  In practice, it also provides a solution where the number
of provisioned narrow-band SS7 signalling links becomes too great,
and the infrastructure for broadband signalling links (ATM SAL
links) does not exist or is cost prohibitive.  Real world cases
are large scale VLR and HLR, which often far surpass the need for
more than 32 narrow-band signalling links.  A number of groups of
link-sets of narrow-band signalling links can be replaced with a
single M2PA link.

Choice between the two is more a matter of interconnection
agreements, network access and provisioning, economic factors and
legacy equipment considerations that are specific to a given
jurisdiction and installation.  The decision is the stuff of
Telecommunications Engineering, and I don't think that there are
any useful simple rules.

There is some general discussion in RFC 2719.

--brian

-- 
Brian F. G. Bidulock
[email protected]
http://www.openss7.org/