The transport standards define ways to establish a communication channel between a client and a service. The communication can be synchronous or asynchronous, meaning that the client blocks waiting for an answer from the service or not, respectively.
| Standard | Reference | Status | Standards organization |
Sponsors |
|---|---|---|---|---|
| HTTP (HyperText Transfer Protocol) | [Fielding99] | standard 1.1 | -- | |
| SMTP (Simple Mail Transfer Protocol) | [Klensin01] | standard | -- | |
| HTTPS (HTTP-Secure) | [Rescorla00] | standard | -- | |
| HTTPR (HTTP-Reliable) | [Parr02] | proposal | -- |
The most used transport for Web Services is
HTTP. A common asynchronous transport is SMTP.
There are also non-standard transport implementations
using message queue systems.
The transport can provide additional features to
the communication.
For instance, when using HTTP transport,
security can be enhanced with HTTPS
and reliability with HTTPR.
However, relying on these solutions makes the
Web Service transport-dependent.
[Fielding99]
Fielding, R.; Gettys, J.; Mogul, J.; Frystyk, H.; Masinter, L.; Leach, P. & Lee, T.B.,
Hypertext Transfer Protocol -- HTTP/1.1,
IETF,
1999
http://www.w3.org/Protocols/rfc2616/rfc2616.txt
[Klensin01]
Klensin, J.,
Simple Mail Transfer Protocol,
IETF,
2001
http://www.ietf.org/rfc/rfc2821.txt
[Parr02]
Parr, F.,
HTTPR Specification,
IBM,
2002
http://www.ibm.com/developerworks/webservices/library/ws-httprspec/
[Rescorla00]
Rescorla, E.,
HTTP Over TLS,
IETF,
2000
http://www.ietf.org/rfc/rfc2818.txt