add loopback ping command to osmopcu
Right now testing of traffic flow through osmopcu involves entire stack of sgsn, ggsn etc.
Would be nice to have vty command which could trigger simple ping-like traffic towards given imsi without waiting for external llc to arrive or phone to start network activity. This would create DL TBF and trigger UL TBF creation upon phone's response.
- interface: do we need anything more complex than "ping IMSI TIMES SIZE"?
- what to do if UL and/or DL TBF already exist for a given imsi? Easiest would be to just quit with warning.
- what kind of packet(s) shall we send to make sure phone will respond? We don't know phone's ip or it might not have one at all.
#1 Updated by laforge over 2 years ago
I don't think this is the right approach, sorry.
an ICMP ping is so many layers higher than the PCU itself, (LLC, SNDCP, IP, ICMP) and far in the user plane. Also, you need the entire SM layer to establish a PDP context first on the signalling plane before sending user plane packets, and befor the user plane even has an IP address assigned.
I think what would more match the level of abstraction of a PCU was
a) the ability to send some kind of signalling LLC message(s) that trigger a response from the phone
b) the ability to send some specific messages for handset testing (I think I saw some references to that, but don't recall the details).