transport protocol used in SOAP web services

[Rodrigo Bossini]

Hi,

I'm starting in the web service world, and everything is new to me.

I hear a lot about "web services" protocol.

As per my understading, a web service uses the SOAP protocol to send XML data over HTTP protocol.


I heard also that there are Rest web services, which do not use SOAP.

So I ask:

What is the standard transport protocol that is used by a web service?
TCP, UDP or what?

Also, does Rest web services use HTTP too?

And, does a web service work exactly the same way a HTTP "post" method works? What transport protocol does an HTTP post method use?

[Ulf Dittmer]

SOAP is not a protocol, but a data format. It does not specify the protocol to be used for transporting it. The vast majority of web services -SOAP, REST, or otherwise- use HTTP as the transport protocol. But for SOAP in particular, other protocols have been used, like raw TCP, email and messaging. REST is very much tied to HTTP, though.

[Rodrigo Bossini]

Ulf Dittmer wrote:SOAP is not a protocol, but a data format. It does not specify the protocol to be used for transporting it. The vast majority of web services -SOAP, REST, or otherwise- use HTTP as the transport protocol. But for SOAP in particular, other protocols have been used, like raw TCP, email and messaging. REST is very much tied to HTTP, though.

When using HTTP, I assume it also uses TCP, "under" HTTP, in the transport layer. Or am I wrong?
Also, SOAP stands for "Simple Object Access Protocol", so it must be a protocol.

[Ulf Dittmer]

When using HTTP, I assume it also uses TCP, "under" HTTP, in the transport layer.

That's correct, HTTP relies on TCP and IP.

SOAP stands for "Simple Object Access Protocol", so it must be a protocol.

And still, it's not. And these days, SOAP is no longer an acronym, as its Wikipedia entry mentions in the first paragraph.