IP fragmentation is an Internet Protocol (IP) process that breaks datagrams into smaller pieces (fragments), so that packets may be formed that can pass through a link with a smaller maximum transmission unit (MTU) than the original datagram size. The fragments are reassembled by the receiving host.
Transparent Fragmentation - the router doing the fragmentation breaks up oversized packets and addresses them all to the same exit router. The exit router re-assembles the fragments and forwards original packet. This is called transparent fragmentation because it is invisible to the other networks in the path and to the hosts.
Problems in Transparent Fragmentation :
1) All packets must exist the same router; doesn't work for a connectionless network.
2)Overhead and delay involved with repeated fragmentation and reassembly.
Nontransparent Fragmentation - once a packet is fragmented, it is not reassembled until it reaches the destination.
Problems in Nontransparent Fragmentation :
1) Overhead is increased since the ratio of data to header is worse.
2)Every host must be able to reassemble.
3)Multiple layers of fragmentation are possible. (Some networks may need to fragment the fragments.)
In IPv4, non-transparent fragmentation is used.
For more information refer here : http://productdevelop.blogspot.in/2013/09/differentiate-between-transparent-and.html
