Idea for synchonous logging/review of debug + GSMTAP

Harald Welte laforge at
Tue Jan 29 12:33:14 UTC 2013

Hi Alexander,

On Tue, Jan 29, 2013 at 04:11:26PM +0400, Alexander Chemeris wrote:

> 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
> the GSMTAP?

I would treat those two independent.  The case for GSMTAP is simply to
have a synchronous / monotonic log (pcap in this case) that combines
both actual packets on Gb and Um, as well as the human-readable log
messages generated by the PCU code in between.

As for the human-readable PCU log messages, I would suggest something
like pre-fixing all of them with the TLLI in the beginning like
[1a2b3d4e] at the start of every line.  I would guess that for most of
the log messages, the TLLI to which they relate should be known.  The
same is not the case for other identifiers like the IMSI.

- Harald Welte <laforge at> 
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)

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