This tries as good as possible to fit the IPA/SCCPlite stacking into the
existing SIGTRAN/SS7 code architecture/model. To the user, the IPA
protocol looks like yet another protocol on the same level as the choice
between SUA and M3AU. On the inside, things are obviously quite
different.
We need to handle TCP with IPA framing instead of SCTP for both server
and client. We also implement an alternative "ASP FSM" for IPA, which
takes care of the CCM handshake (ID_REQ/ID_RESP/ID_ACK/ID_ACK2) for both
client and server mode.
In server mode, we use the 'unit name' as identifier to look up the AS,
similar to how we use a routing context to look up the AS in the xUA
case.
We also have to bypass activating the default layer manager in the
simple client to make sure we don't run into even more complexity.
What's missing right now is some way to manually override/set the point
codes. As IPA/SCCPlite is missing any routing label, we currently
simply generate one with SPC=0/DPC=0, which will obviously not work in
most configurations.
Change-Id: I9098574cddeba10fcf8f1b6c196a7069a6805c56
For classic xUA this is not needed, as the server doesn't have to react
to establishment of the SCTP connection. The client will start with an
ASP_UP_REQ. However, in upcoming IPA support, the FSM will need to
react on this event.
Change-Id: Ib10914b27f8761ea44a0fdba96c045821223722a
This is what aims to be a rather complete/proper implementation of the
SIGTRAN + SS7 protocol suite. It has proper abstraction between the
layers with primitives, finite state machines for things like the AS and
ASP state machines, support for point code routing, etc.
What's not implemented at this point:
* re-integration of pre-existing SUA (pending)
* actual MTP2 and physical E1/T1 link support
* different trafic modes like broadcast/fail-over/load-balance
Change-Id: I375eb80f01acc013094851d91d1d3333ebc12bc7
Harald Welte