NE40E version is V6R1,BSC6000 version:V9R8C12SP27, the topology is:BSC6000----(MTU:1500)---PE1(MTU:1500)--- (MTU:1500)---P1--(MTU:1500)-----PE2--(MTU:1500)----SGSN1; The customer complain that the GPRS customer cannot browse pictures at web site properly.
the GPRS customer cannot browse pictures at website
Because when we reduce the MTU the problem still cannot be solved. Then we discuss with Wireless R&D, after discussion we know that because BSC6000 version cannot support the IP packet to be sliced twice, when BSC will drop the IP packets which are sliced twice, then it cause GPRS customer cannot browse pictures at website
As maintains experience, we know we need reduce the interface MTU when the physical link is not so good, to let the big packets can be carried by network. But when you reduce MTU the network still cannot carry the big packets properly we should also consider whether all the L3 IP elements in the network can support the IP packets to be sliced twice.