The Comparisons of ATM, IP, and LAN Technologies
 
ATTRIBUTEETHERNETIEEE 802.3IEEE 802.5IPATM
Application support?Asynchronous data with some voice, no QoS.Asynchronous data with some voice, no QoS.Asynchronous dataAsynchronous data with some voice and video, but not so designed.Asynchronous, synchronous voice, video, and data.
Connection mode?
Connectionless
Connectionless
Connectionless
Connectionless
Connection-oriented
Congestion management?Collison detection
Collison detection
Priority is 8 levels with the passing of a token.
None
Yes, traffic tagging with cell loss priority, and possible traffic discard.
Method of identifying traffic?
48-bit MAC address
48-bit MAC address
48-bit MAC address
32-bit IP address
Virtual path and virtual channel identifiers.
Congestion notifications?
None
None
None
None
Yes, located in the Payload Type Identifier.
Traffic tagging technique?
None
None
None
None
Uses the cell loss priority bit.
Packet Data Unit size?
Variable
Variable
Variable
Variable
Fixed at 53 bytes (PDU is a cell)
Sequencing of traffic?
No
No
No
No
Cell header, no; for ATM Adaption Layer (AAL) payload, depends on the AAL type.
Encapsulation header?
Yes, Ethertype
Yes, Logical Link Control (LLC)
Yes, LLC
Yes, IP Protocol ID
Yes, typically LLC
ACKs/NAKs retransmissions?
No
No
No
No
Only for signaling traffic on SVCs.

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Extracted from "Comparison of ATM Interfaces and Data Units", Table 1-3, pages 10-11, ATM Volume III by Uyless Black.

Date of last revision: 17 December 2001.