Web service protocol stack consists of 4 layers. This can be described as follows :
a) Service transport : This is the first layer that helps in transporting XML messages between various client applications. This layer commonly uses the below-mentioned protocols:
* HTTP(Hypertext Transport Protocol)
* SMTP(Simple Mail Transport Protocol)
* FTP(File Transfer Protocol)
* BEEP(Block Extensible Exchange Protocol)
b) XML messaging : This layer is based on the XML model where messages are encoded in common XML format which is easily understood by others. This layer includes
* XML-RPC
* SOAP(Simple Object Access Protocol)
c) Service description : This layer contains descriptions like location, available functions, and data types for XML messaging which describes the public interface to a specific web service. This layer includes:
* WSDL(Web Service Description Language)
d) Service discovery : This layer is responsible for providing a way to publish and find web services over the web. This layer includes:
* UDDI(Universal Description, Discovery, and Integration)
