A Question in xyzws mock exam

[Yi Si]

I did mock exams on http://www.xyzws.com/scdjws.do?cat=scdjws&smenu=MOCK, found the following question.

What are the main benefits of SOAP over HTTP bindinng?
1.SOAP messages are guaranteed to be delivered.
2.SOAP messages are universally supported across different platforms.
3.SOAP messages can be encrypted and security.
4.SOAP messages can be able to pass through firewalls

I selected 2,3,4 but the answer provided is 1,2,4.
I can't make sense that option 1 is correct and option 3 is wrong. Could somebody make a detail explaination?

[Nagendra Inuguri]

Yes. I agree that 1st option is wrong because the underlying transport protocol (http) doesn't gaurantee the delivery of messages.

I am not clear about 3rd option. SOAP specification doesn't specify any thing about security. However jax-rpc allows SOAP messages to be signed or encrypted. Please correct me if I am wrong here.

Thanks,
Nagendra

[wise owen]

1.SOAP messages are guaranteed to be delivered.
HTTP is a "reliable" protocol in that it delivers messages at most once, in order, and with a definite acknowledgement for each message delivery or delivery failure.
We will make changes for this answer. Any suggestions for this answer are welcome.
Thanks.

3.SOAP messages can be encrypted and security.
Nothing to do with HTTP protocol.

[ August 15, 2006: Message edited by: wise owen ]

[Yi Si]

About option 1 I read following in blueprint :

1.3.3 Reliability, Availability, and Scalability
For Web services, reliability may be more
difficult to achieve because of the unreliable nature of the underlying transport,HTTP; HTTP provides only best-effort delivery and does not guarantee packet or in-order delivery. A Web service is considered more reliable the more easily and automatically it can handle changes in use patterns and system configurations.

About option 3 I think it is a bit ambiguously, If I say that the BP1.0 limits the underlying transport protocol to HTTP(http binding).Someone
thinks it means including HTTPS ,others maybe not.
Maybe this concept is not fit as a option.
[ August 15, 2006: Message edited by: Yi Si ]