and as quickly as problems come, they can also go. In addition, due to radio conditions or intra-system handovers between the 3GPP network technologies, the bandwidth and latency characteristics can change in either direction. Hence, the bandwidth available for a UE can suddenly either decrease or increase. In addition, the network latency can vary greatly. Where in the best case the network the Round Trip Time (RTT) can be few milliseconds, in bad conditions RTT of multiple seconds is not uncommon. An interesting characteristic of the 3GPP network is the network Maximum Transmis- sion Unit (MTU) size. MTU is the maximum size of a single packet that the network can carry without the packet having to be fragmented that is, split into two or more IP packets. The standardized MTU of 3GPP networks is 1500 bytes. This is to be similar with other networking technologies, such as the Ethernet [53], as they use the same MTU size. As a matter of fact, 1500 bytes is the default MTU for most hosts. However, the 3GPP mobility management is provided by tunneling in the network. Let's consider this for a moment. The tunneling providing the transport for the PDP Contexts and EPS Bearers creates overhead. In GTP, it is the size of the IP, the UDP, and the GTP headers. At minimum, with IPv4 based transport this is 20 bytes for the IPv4 header, 8 bytes of the UDP header, and another 8 bytes minimum for the GTP. Hence, we are talking about a minimum of 36 bytes of overhead. If we now add a user-plane packet with an MTU of 1500 bytes we have 36 + 1500 = 1536 bytes. The probable MTU of the transmission technology that connects the mobile network elements to each other is 1500 bytes. The technology mostly used, at least in the core network, is Ethernet. Now we see the dilemma: the transmission path's MTU is 1500 bytes, but the packet with all its tunneling overhead is 1536 bytes. Either it will not fit, or it has to be fragmented into two separate packets. Dropping the packet in the network is of course not very nice, but fragmentatio