Re: channel availability

20.11.2015 11:12, Harald Welte пишет: I don't see this one but logging level lgtp debug and logging level gprs debug did the trick, thanks! Doh! As far as I recall sgsn/ggsn ignores apn (btw, there's nothing while searching for "apn" in wiki) but I forgot that phone still got to have something set as apn ("internet" works fine) in order to start actually using gprs. I should have guessed - the lack of gprs indicator on the phone means it did not actually attempt to use it. Now, it works, although just one way for some reason. I can see activated pdp context in sgsn vty: OsmoSGSN# show pdp-context all PDP Context IMSI: 901708776992222, SAPI: 3, NSAPI: 5 APN: internet PDP Address: IPv4 192.168.0.2 SGSN PDP Context Statistics: User Data Messages ( In): 16 (0/s 0/m 16/h 0/d) User Data Messages (Out): 0 (0/s 0/m 0/h 0/d) User Data Bytes ( In): 1032 (0/s 0/m 1032/h 0/d) User Data Bytes (Out): 0 (0/s 0/m 0/h 0/d) Also I see the dns requests in tcpdump over tun0 interface. The problem is the above 0 Out - nothing has been sent to the mobile. The masquerading on the host seems to work fine at first glance: ping -S 192.168.0.3 8.8.8.8 gets expected response (here 192.168.0.3 is the address from the space assigned to phones). However, none of the phone's requests receive reply. On the other hand if I try to ping phone directly from the host than I got reply just fine, counters got updated in sgsn, messages are visible in wireshark etc. So it seems like the osmocom side of things is doing fine and the remaining issue is somewhere on the host. I would blame iptables but I've checked that no blocking rules installed and all policies defaults to accept for both regular and nat tables. Anyway, will keep digging, thanks for help! cheers, Max.