diff options
authorMax <>2018-01-04 12:52:12 +0100
committerHarald Welte <>2018-01-05 12:46:38 +0000
commit98bb147bbd53eb03180221d13cd6a30d05ee893c (patch)
parenta8d2935f830900dc0baeca0ddc1ae7391900f623 (diff)
Describe gsmtap log destination
-rw-r--r--common/images/wireshark-gsmtap-log.pngbin0 -> 226020 bytes
3 files changed, 25 insertions, 1 deletions
diff --git a/.gitignore b/.gitignore
index 67c2f69..3c72c7f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,5 @@
diff --git a/common/chapters/logging.adoc b/common/chapters/logging.adoc
index 85975bb..beb1341 100644
--- a/common/chapters/logging.adoc
+++ b/common/chapters/logging.adoc
@@ -144,6 +144,31 @@ OsmoBSC(config-log)#
In the example above 98 is the desired size of the ring buffer (number of messages). Once it's filled,
the incoming log messages will push out the oldest messages available in the buffer.
+==== Logging via gsmtap
+When debugging complex issues it's handy to be able to reconstruct exact chain of events. This is enabled by using GSMTAP
+log output where frames sent/received over the air are intersperced with the log lines. It also simplifies the bug handling
+as users don't have to provide separate .pcap and .log files anymore - everything will be inside self-contained packet dump.
+It's configured as follows:
+OsmoBSC> enable
+OsmoBSC# configure terminal
+OsmoBSC(config)# log gsmtap
+The hostname/ip argument is optional: if omitted the default will be used. The log strings inside GSMTAP are already
+supported by Wireshark. Capturing for `port 4729` on appropriate interface will reveal log messages including source file
+name and line number as well as application. This makes it easy to consolidate logs from several different network components
+alongside the air frames. You can also use Wireshark to quickly filter logs for a given subsystem, severity, file name etc.
+.Wireshark with logs delivered over GSMTAP
+Note: the logs are also duplicated to stderr when GSMTAP logging is configured.
==== Logging to a file
As opposed to Logging to the VTY, logging to files is persistent and
diff --git a/common/images/wireshark-gsmtap-log.png b/common/images/wireshark-gsmtap-log.png
new file mode 100644
index 0000000..12fde6f
--- /dev/null
+++ b/common/images/wireshark-gsmtap-log.png
Binary files differ