Clarification in Web service

I need a clarification in calling a web service
1. The web service resides in the internet and I am having the url of the wsdl file. While connecting using 6.5 connector or 7.1 descriptor if I specify the URL of the wsdl file, it is not accepting. Instead if I save the wsdl locally and if I specify the local path of wsdl in wm it is accepting. Why so ?
2. While connecting to a webservice that resides in internet wm throws a connect exception. Then I changed the http proxy in the wm administrator. After that It gave the following exception:

Proxy Authorization Required: Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy filter is denied. )

I gave the right username and password. But still its giving error.

Kindly help me out.

for the first question of yours, the reason why you are not able to create the web service connector using the WSDL URL because there made some authentication required by the server where the WSDL is located in order to access. So when u save it on your local disk your webMethods ahve all the rights to access the WSDL file.

for the second one I think there are some connection authentication required for the Proxy servers access.

To get the best error try to uses step-by step compilation, you will get clear cut error