AppleTalk - Six-layer Protocol Suite
Network Layer:
- DDP - Datagram Delivery Protocol
Transport Layer:
- RTMP - Routing Table Maintenance Protocol, maintains and broadcasts routing information (every few seconds)
- AEP - AppleTalk Echo Protocol, sends datagrams to other nodes in the network to determine their existence
- ATP - AppleTalk Transaction Protocol, determines whether requests are lost or delayed
- NBP - Name Binding Protocol, translates device a name into AppleTalk address