Internetwork Packet eXchange Fragmentation
IPXF , I nternetwork P acket e X change F ragmentation is one of Novell developed network protocol as an extension of IPX .
A large UDP - packet (User Datagram Protocol) can not be sent directly over IPX as UDP packets up to 64 KiByte can be large, IPX packets on the other hand by the MTU be limited. As a result, large UDP packets must be broken up (fragmented) before they can be sent over IPX. To allow for large split UDP packets, UDP runs the packets over the IPXF layer instead of IPX.
For the IPXF user, IPXF presents itself like IPX. That means that the data packets for IPXF like destination IPX address / socket are specified together with the packet. (For UDP, source sockets and destination sockets are 0x9092.)
IPXF is defined in RFC 1791 .
The protocol in the OSI model
The protocol in the OSI model (see in comparison the TCP / IP reference model , OSI model ):
| OSI layer | English | classification | TCP / IP layer | classification | IPX / SPX / NCP | |
|---|---|---|---|---|---|---|
| 7th | application | Application | Application- oriented |
application | End to end (multihop) |
NCP |
| 6th | presentation | Presentation | ||||
| 5 | meeting | session | ||||
| 4th | transport | transport | Transport- oriented |
Host to host |
SPX , TCP , UDP | |
| 3 | Mediation | Network | Internet | Point to point |
IPX , IPXF | |
| 2 | Fuse | Data link | network |
Ethernet Token Ring FDDI ARCNET |
||
| 1 | Bit transfer | Physical | ||||
Web links
- RFC 1791 - TCP And UDP Over IPX Networks With Fixed Path MTU