Unknown issue with GGSN/SGSN

[Chris Rankine]

I am trying to implement an experimental EDGE deployment using one of the
DCS1800 models.  (If needed for debugging purposes, I can request access to
a GSM900 for GPRS only testing).  I have everything compiled and running
with the newest builds as of a few or two ago.  EDGE works most of the time,
however randomly it stops working.  I have the SGSN and GGSN running, and
typically during these down periods I will see messages appearing on the
SGSN, but none of the typical traffic flowing messages on the GGSN (typical
messages being "Received packet from tun!" and "encaps_tun. Packet received:
forwarding to tun").  Typically if I wait a period of time, sometimes about
2 minutes, other times for a long time, then the connection returns.  During
this entire time the phone still displays the "E" meaning it believes it has
an EDGE connection.  If I reboot the phone I will get the PDP entry deleted
and requested messages.  As for the SGSN, I am new to GPRS and EDGE and I am
not familiar with a lot of the terms that are appearing, so I can not
comment on what is good or bad.  I get the same results if I put three IPs
on one VM and have it running OpenBSC, OpenGGSN, and the OpenBSC based SGSN,
as compared to when I give one VM to OpenBSC and another dual homed VM hosts
OpenGGSN and SGSN.

I guess what I am asking is what do you suggest I should be looking into to
try to figure out what is causing this problem?  I have two old Android
phones to play with..  So, at least for the Android phones I have better
access at debugging issues on the phone.  Attached below are the relevant
parts of the GGSN conf, SGSN conf, and openBSC conf.  Thanks for any
suggestions.

Chris Rankine

##### /etc/ggsn.conf

fg
debug
listen 192.168.21.189
pcodns1 130.207.244.251
pcodns2 130.207.244.251


###### osmo_sgsn.cfg

sgsn
 gtp local-ip 192.168.21.188
 ggsn 0 remote-ip 192.168.21.189
 ggsn 0 gtp-version 1
ns
 timer tns-block 3
 timer tns-block-retries 3
 timer tns-reset 3
 timer tns-reset-retries 3
 timer tns-test 30
 timer tns-alive 3
 timer tns-alive-retries 10
 encapsulation udp local-ip 192.168.21.188
 encapsulation udp local-port 23000
 encapsulation framerelay-gre enabled 0
bssgp


##### openbsc.cfg

network
 network country code 1
 mobile network code 1
 short name OpenBSC
 long name OpenBSC
 auth policy closed
 location updating reject cause 13
 encryption a5 0
 neci 1
 rrlp mode none
 mm info 1
 handover 0
 handover window rxlev averaging 10
 handover window rxqual averaging 1
 handover window rxlev neighbor averaging 10
 handover power budget interval 6
 handover power budget hysteresis 3
 handover maximum distance 9999
 timer t3101 10
 timer t3103 0
 timer t3105 0
 timer t3107 0
 timer t3109 0
 timer t3111 0
 timer t3113 60
 timer t3115 0
 timer t3117 0
 timer t3119 0
 timer t3141 0
 bts 0
  type nanobts
  band DCS1800
  cell_identity 0
  location_area_code 1
  training_sequence_code 7
  base_station_id_code 63
  ms max power 40
  cell reselection hysteresis 4
  rxlev access min 0
  channel allocator ascending
  rach tx integer 9
  rach max transmission 7
  ip.access unit_id 3 0
  oml ip.access stream_id 255
  gprs mode egprs
  gprs routing area 1
  gprs cell bvci 2
  gprs nsei 1
  gprs nsvc 0 nsvci 1
  gprs nsvc 0 local udp port 23000
  gprs nsvc 0 remote udp port 23000
  gprs nsvc 0 remote ip 192.168.21.188
  trx 0
   rf_locked 0
   arfcn 514
   nominal power 70
   max_power_red 0
   rsl e1 tei 0
    timeslot 0
     phys_chan_config CCCH+SDCCH4
    timeslot 1
     phys_chan_config SDCCH8
    timeslot 2
     phys_chan_config TCH/F
    timeslot 3
     phys_chan_config PDCH
    timeslot 4
     phys_chan_config TCH/F
    timeslot 5
     phys_chan_config PDCH
    timeslot 6
     phys_chan_config PDCH
    timeslot 7
     phys_chan_config PDCH
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osmocom.org/pipermail/openbsc/attachments/20110107/901ee65b/attachment.htm>