| Transfer
modes & connections summarized |
| Transfer
modes |
| Connection
types |
| ATM |
| Circuit
switching |
| Connection
oriented |
|
|
|
| PSTN |
||
| ISDN |
||
| PCM |
||
|
|
|
|
| - developed for
voice |
|||
| - nowadays also
for data |
|||
| - well-specified
delays |
|||
| - echo problems |
|||
| Frame-relay |
| X.25 |
| Packet
switching |
| Connectionless |
|
|
|
|
| - developed for
data |
|||
| - nowadays also
for voice |
|||
| - Statistical
multiplexing |
|||
| - variable delays |
|||
|
|
|
|
| - broadcasting |
|||
| - modest error
rates |
|||
| often accepted |
|||
| - fast data in
good channels |
|||
|
|
| IP, Frame-relay |
|
| ATM |
|
| IP,
UDP* |
