SUNYNet Technology Services

SUNYNet Current Architecture

Case 9:   No Intranet Accessing campuses through AT&T
(see drawing, below)

Listing of Cases

Method of delivering Internet and intranet:
In this case, the campus and its application users have determined that the AT&T Internet will suffice for all of its SUNY-to-SUNY communications. This determination might be based on the campus's having no intranet applications, or none that require encryption, tunneling, or prioritization. Since the campus uses AT&T it will have fewer hops and virtually no points of congestion in the core network when communicating with the other campuses that use AT&T exclusively. AT&T lines terminate on campus in routers (the blue, cross-shaped boxes) that are owned and operated by AT&T. In this case, the campus has chosen not to have SUNYNet Operations operate the intranet router (grayed-out, cross-shaped box). This absence will prevent it from creating the tunnels that are needed to: 1) transmit DECNet to other campuses, 2)communicate exclusively over AT&T with campuses that use AT&T only for intranet applications (see Case 6), and 3) prevent asymmetrical routing (a performance issue) with campuses that use both AT&T and another ISP (see Case 5). These issues are not insignificant in theory, but in the case of this campus, a careful analysis of actual projected use showed that they will not matter. If problems develop, the remedy is simply to add a SUNYNet router on campus, i.e. move to Case 4.

The campus may, on its own, use AT&T's CoS (Class of Service) feature if it wants better performance for any class of IP traffic coming from other SUNY campuses. This feature carries an additional monthly fee, and allows the routers on both ends of the campus-to-AT&T link to give priority to identified traffic in both directions.

Roles of the Routers:
IP traffic that is bound for off-campus destinations gets directed to the AT&T (blue) router(s) which send(s) it into its core network (blue cloud). The network delivers it to SUNY destinations, or to other AT&T Internet subscribers and Internet Service Providers  worldwide.

All of the public IP address space for the campus will be announced to the Internet by AT&T.