Idea for synchonous logging/review of debug + GSMTAP

Alexander Chemeris alexander.chemeris at
Tue Jan 29 12:11:26 UTC 2013

Hi Harald,

On Tue, Jan 29, 2013 at 2:22 PM, Harald Welte <laforge at> wrote:
> one of the problems when debugging PCU issues is: How to take proper
> logs on-site where a problem shows up and give them back to the
> developer(s) for analysis.  If you capture the PCU stdout or configure
> file-based logging, you will have a hard time corellating that with PCAP
> traces taken on the RLC/MAC side and/or on the Gb side.
> Therefore I propose a new idea here and would like to get your review:
> What about implementing a "GSMTAP" log target for libosmocore?  This way
> we could encapsulate the log messages into a special GSMTAP message,
> which would be sent synchronously in the GSMTAP stream together with
> RLC/MAC messages on the lower end.

Yes, debugging PCU is PITA and we've been discussing logging
improvements with Ivan for some time already. From our discussions it
seems that the biggest issue is to correlate log messages with the
actual user and/or session. How do you want to solve this issue with

PS In general, the proposal to use GSMTAP is ... interesting. :)

Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио

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