reference is now made to fig1 , which is a simplified conceptual illustration of a multi - protocol authentication and authorization system , constructed and operative in accordance with a preferred embodiment of the present invention , and additionally to fig2 a and 2b , which , taken together , is a simplified flowchart illustration of an exemplary method of operation of the system of fig1 , operative in accordance with a preferred embodiment of the present invention . in the system and method of fig1 and 2 a - 2 b , a requester , via a computer - based client application 100 , sends a request 102 , such as an http - based request , via a network 104 , such as the internet , to a server 106 , which may be an application server such as the websphere ™ application server commercially - available from international business machines corporation , armonk , n . y ., usa . request 102 is received at server 106 by a request interceptor 108 , such as the websphere ™ trust association interface ™ ( tai ), which manages the request authentication process , such as via an authenticator 110 . using conventional techniques , request interceptor 108 preferably consults a database 112 to determine whether the requester is known , and whether the request is to be trusted as - is , or whether a challenge is to be issued . if the latter , request interceptor 108 issues the challenge to the requester , asks authenticator 110 to validate the digest returned by the requester , and authenticates the request if the digest is valid . in accordance with the present invention , request interceptor 108 may likewise authenticate a request 114 received from client 100 and that is based on a different protocol , such as sip . it is appreciated that request interceptor 108 may be configured to receive and authenticate requests from multiple protocols . once a request has been authenticated , request interceptor 108 authorizes the request , such as by determining whether the request is to be forwarded to the requested application , and , if so , what level of access to the requested application the requestor is to receive . for example , in the java ™ 2 platform , enterprise edition ( j2ee ™), commercially available from sun microsystems , inc ., santa clara , calif ., usa , one or more roles are defined for an application , where activity may be constrained based on the role that an authenticated requester has been given . for example , users in a manager role might be able to delete inventory , while users in an employee role might not . in accordance with the present invention , where the same requestor sends different requests to server 106 using different protocols , such as http and sip , multi - protocol authentication decisions and / or authorization decisions may be made using multi - protocol criteria that take into account the very fact that different requests may be made using different protocols . for example , request interceptor 108 might not authenticate a sip - based request unless the requestor has been authenticated for an http - based request . similarly , request interceptor 108 might constrain the authenticated requestor to one role where the requestor is authenticated for both http - based and sip - based requests , and a different role where the requestor is authenticated for an http - request only , and yet another role where the requester is authenticated for an sip - request only . different roles may also be assigned based on whether multiple requests using multiple protocols are made simultaneously ( i . e ., within a predefined time window ) or at different times . reference is now made to fig3 , which is a simplified conceptual illustration of a request interceptor architecture , constructed and operative in accordance with a preferred embodiment of the present invention . in fig3 a request interceptor 300 is shown having multiple protocol interfaces 302 , 304 , and 306 , each providing execution points for requests based on different protocols , such as http , sip , and diameter . a shared memory 308 is preferably provided whereby protocol interfaces 302 , 304 , and 306 may share information relating to the processing of requests , and to which multi - protocol logic may be applied as described hereinabove . each of protocol interfaces 302 , 304 , and 306 is independently responsible for managing the authentication and authorization of requests based on its protocol . base classes 310 are provided embodying protocol - independent logic to complement the protocol - dependent logic of protocol interfaces 302 , 304 , and 306 . thus , while each protocol is provided with its own execution points as it interfaces with request interceptor 300 , a multi - protocol view may be provided by allowing each protocol to interact independently with request interceptor 300 , while providing a shared environment linking the individual protocol interfaces to each other , as well as to protocol - independent logic . reference is now made to fig4 , which is a simplified conceptual illustration of the multi - protocol authentication and authorization system of the present invention implemented as part of a converged application environment , constructed and operative in accordance with a preferred embodiment of the present invention . in the environment of fig4 a client application 400 ( represented pictorally as a computer on which client application 400 may reside ) communicates via a network 402 , such as the internet , with an application server 404 in a cluster 406 of application servers , one of several clusters that is found in a clustering environment 408 . a load balancing and routing mechanism 410 is provided for determining which server in which cluster an incoming message from client 400 should be routed . each application server 404 may employ the request interceptor mechanisms described hereinabove in support of one or more converged applications hosted by application server 404 . each converged application preferably supports session affinity for incoming requests from client 400 using different transport protocols , where requests that are part of the same converged session , regardless of the transport protocol used , are directed to the application server where the session information resides . in accordance with conventional techniques , the converged application maintains the state of a session , while requests over different transport protocols for the converged application typically include encoded information that is used to maintain session affinity . load balancing and routing mechanism 410 recognizes the session via the encoded information , such as in the form of a “ cookie ,” received from client 400 , and directs the request to the converged application . session affinity for converged applications can be used to direct requests to the application server instance where the multi - protocol request interceptor shared memory state resides , allowing for multi - protocol authorization decisions as described hereinabove . it is appreciated that one or more of the steps of any of the methods described herein may be omitted or carried out in a different order than that shown , without departing from the true spirit and scope of the invention . while the methods and apparatus disclosed herein may or may not have been described with reference to specific computer hardware or software , it is appreciated that the methods and apparatus described herein may be readily implemented in computer hardware or software using conventional techniques . while the present invention has been described with reference to one or more specific embodiments , the description is intended to be illustrative of the invention as a whole and is not to be construed as limiting the invention to the embodiments shown . it is appreciated that various modifications may occur to those skilled in the art that , while not specifically shown herein , are nevertheless within the true spirit and scope of the invention .