30 Jul
2009
30 Jul
'09
11:03 p.m.
On Thu, Jul 30, 2009 at 01:00:46PM +0200, Nordin wrote:
Hi,
according to the wiki for the nanobts:
* 0x00 RSL messages as per GSM 08.58
* 0xfe ip.access specific messages
* 0xff OML messages as per GSM 12.21
I assume this is the so called SAPI?
no. SAPI only exists in E1 based A-bis.
Cause I read some Abis articles that for RSL and OML
is resp. 0 and 62.
I just want to be sure there are some value differences.
A-bis over E1 is what the BS-11 uses. ip.access has their own proprietary
protocol stacking and A-bis dialect. There is no public documentation about
it, apart from what we deducted from protocol traces and implemented in OpenBSC
/ wireshark and put into the OpenBSC wiki.
In any case, the Layer 2 (Q.921 on E1, with TEI and SAPI) is completely
uninteresting. All you should care about is layer 3 (12.21 OML and 08.58 RSL).
Whatever is below is the transport layer and does not actually have any actual impact on
the GSM netwokr
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
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