Ivo Sedlacek writes: > 3GPP spec expects that if the client (User Equipment) supports the > TIMEOUT_PERIOD_FOR_LIVENESS_CHECK configuration attribute, then the client > (User Equipment) *enforces* the timer value indicated in the > TIMEOUT_PERIOD_FOR_LIVENESS_CHECK configuration attribute in CFG_REPLY sent by > server (Evolved Packet Data Gateway). > > I.e. it is an intruction, not a suggestion.
Yes, but there is nothing there to say what the server will do if the UE misbehavies. I.e. if the UE simply ignores the timeout period it received and instead of the server requested 300 seconds uses 30 seconds for the timeout period. Is the server going to detect this? Is the server going to kick the UE out because it misbehaves and sends liveness checks too often? On the other hand IKEv2 RFC also allows sending liveness checks at any time when client thinks there might be issues (for example it receives ICMP message), so server cannot kick UE out just because it does liveness checks too often. On the other hand if server asks for 30 seconds, and UE uses 300 seconds, is the server going to assume that UE is dead as it didn't send liveness check in last 30 seconds? Is it going to free the resources of the UE after some amount of time when it should have received liveness check etc. So as there is no server side behavior described in the 3gpp EPC specification, this is more like suggestion than actual requirement. It is similar than laws we have where you must do something, but even if you do not there is no penalty, i.e. it is unenforceable law. Of course in most cases the UE will follow the liveness check timeout period requested by the EPC, as it does not have any reason not to, but UE might still want to have some limits for those, i.e. even if the server asks liveness checks every second, it might be good idea to make the lower limit to something like 30 seconds... -- kivi...@iki.fi _______________________________________________ IPsec mailing list IPsec@ietf.org https://www.ietf.org/mailman/listinfo/ipsec
