22 Feb
2017
22 Feb
'17
10:19 a.m.
Hi Holger,
On Wed, Feb 22, 2017 at 04:02:17PM +0700, Holger Freyther wrote:
I think for b.) and c.) we will require SIP re-invite
but also need
to look at the AoIP spec to see if they say how to handle this
scenario.
I "think" the assumption in AoIP is that the RTP "originates" from
the
BSC and not from the BTS. As such, there is no change to the RTP
stream parameters in any intra-BSC hand-over. The reasoning/rationale
would be simple: There are still virtually no Abis/IP based BTS in the
field so far, and most commercial systems (even RBS6000 from Ericsson
e.g.) still uses E1/T1 for the Abis. That Abis might be adapted over
some propriatary L2TP-over-IP stacking for the back-haul.
So basically except the Osmocom implementations, and ip.access, I still
don't think there are many native IP based Abis systems out there, and
hence this is considered an implementation detail of the vendor. The A
interface orignates at the BSC, and everything "below" the BSC is
opaque.
But feel free to check yourself, I might remember it wrong.
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
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