Hey, > > We are experiencing network rejections when our device switches from cell > tower to cell tower. > > We have been in contact with our SIM provider, Vodafone, which says that this > is due to us sending delete and create session requests too rapidly (within > 40ms between requests). > > These are Vodafone's comments on the Wireshark trace (see attached) they have > captured on their side: > === > As can be observed in the shared traces, the new create session request was > initiated after less than 40ms since the Delete Session. > Also, it is visible that the session was not terminated internally, the > Credit Control Terminate messages for the initial data session were sent > after the Create session Request. > > Moreover, this SIM is having static IP allocation. > Even if the IP is not assigned by the PGW, after a data session is closed, > the IP assigned for that data session is set in quarantine for a specific > period of time ( not configurable, it is calculated internally by the PGW). > > Based on the above, the reason why the session got rejected is due to the > short period of time between Delete and Create. > === > > Is this a known problem? And is this something we could configure on the > device/modem side? > > Thanks in advance for any insights on this matter! > > Some additional info... > We use NetworkManager to setup the connection with our private APN. > We are using MM 1.18.0 and libqmi 1.30.2 on Linux kernel 4.14.98 > We are using the SIM7100E from Simcom which is running firmware > 4534B06SIM7100E
You need to bring this up to the modem manufacturer, there's nothing in ModemManager that touches that logic. -- Aleksander https://aleksander.es
