Hi, osmocom team members. In order to have an internet connection in UE, we have run OsmoGGSN project to set up GGSN. Also, SGSN is developed in our system. At this step, UE connects to our network core and we can query to an arbitrary site in the UE browser and we see the answer of the query without any problem and everything is OK. But after about 30 or 40 seconds, UE sends "Deactivate PDP Context Request" with SM Cause "SM Cause: Protocol error, unspecified (111)" and the connection is reset and a new "Activate PDP Context Request" is required. What is the reason and how can we solve it? -- *When there is much light, The shadow is deep...*