Rename NAT_IPAC_PROTO_MGCP to IPAC_PROTO_MGCP and place it in
the enum. We need to be prepared to change this number if IPA
is ever going to use it for something else.
The transcoder RESET is using the same extensions to reset all
endpoints on a remote site. This makes sure that all allocations
can be made in a properly configured network.
Assume that if the MSC has assigned a timeslot/multiplex it will
also be used for the MGCP. So we just assume that it was allocated
on the BSC as well... in the worse case we will send a DLCX downstream
but it should be fine.
We are going to have more than one trunk, so all code hardcoding the
multiplex to zero must go. Avoid this kind of problem by saving the
MGCP endpoint number and comparing that.
If the CRCX is failing, we will send a DLCX downstream and the next
time the callagent tries to do a CRCX we will be more lucky. This is
for the case where we have an endp allocated.
We plan to have two different ports for the network and for the
BTS to avoid detecting the BTS and to dynamically allocate the
port to have old data not go to a new socket.
common_vty.c was including bsc_nat.h which tried to
get the sccp/sccp_types.h which is not required to be
installed. Move all structs using/embedding SCCP structures
into the bsc_nat_sccp.h and include. This should fix
the compilation.
The code needs to be refactored but this is fixing the leak for
now. We used to forward everything to the BSC but now we handle
the DLCX locally and this means we need to clear the patched
message. We should refactor it to not generate the patched msg
until a lot later.
In case we can not find the SCCP connection we still want to
free any pending transaction ids and reset the BSC inside the
endpoint. In most cases this should be already done when the
SCCP connection or the whole BSC is gone.
When setting a new MSC timeslot to a SCCP connection check if
any of the existing connections have this timeslot, if so we will
send a DLCX down the stream to make sure it is closed there, when
we will CRCX this new timeslot we will happily reallocate it.
When the SCCP connection goes away, or we get a DLCX from the
network, or the BSC is gone we will send a DLCX message down the
stream as well.
When we receive a CRCX from the network we will forward the CRCX
as usual and send a dummy MDCX after it.
For the DLCX and the dummy MDCX we send a custom MGCP message
that will not provoke an answer. Even if the downstream MGCP GW
will answer we will ignore it due the dummy transaction id that
is not used anywhere else.
This change should make sure that we close the dowstream endpoint
all the time, even when the DLCX arrives after the SCCP connection
is torndown.
We will reset the multiplex in a DLCX message and then
we can reset the multiplex as well...even if the MGCP
connection is staying open. or at least this is a theory.
The MSC likes to leave a connection open during CallControl
when hanging up early enough in the process.
In case we have a stale SCCP connection with an Endpoint that
we want to reassign...use the newest (last) occurence of that
as it is most likely the one we want to handle.
It was possible that the nat detected the core network
gateway as the bts just due being the first to send data
to the port. Fix it by setting a dummy bts_ip to force
the mgcp_network code to compare the in_addr.
This method currently prepends the IPA header and sends
the data. In the future we might be able to use SCTP for
it.
We have to remove the IPA header from the static messages
for that to work.
This code is untested.
E.g. when the MGCP on the BSS is not responding we could block
all of our endpoints. As we are mostly in the middle and forward
bits we will happily reallocate the endpoints.
When not being able to allocate the msgb for the forwarded data
there is no point in keeping and preparing the transaction. So
we can move the msg creation a bit up and only do the allocations
after having done the msgb allocation.
When receiving a DLCX we will now delete the endpoint right away. This
means when a BSS does not respond to the DLCX our endpoint will not
be blocked. E.g. this could happen when the MGCP is restarting or
in similiar conditions. When the BSS is not responding we move the
burden up the chain to the CallAgent. We have to still keep track
of the transaction id and the bsc pointer to keep the mgcp forward
routine working.
This value is copied into the bts_audio_payload when allocating
a BTS MGCP endpoint. For the nat we have actually no interest in
patching MGCP messages. We will patch them to the network because
the code will do it anyway, we will not patch things back to the
BTS.
Holger Hans Peter Freyther
Harald Welte