Understanding the network.pdf - Back to Home

"Classical IP over ATM." Keeping in mind the now-legacy status of
LANE and need for IP over ATM, we will look at LANE and then briefly
discuss Classical IP and its derivatives later in this section.
NOTE
RSVP provides bandwidth reservation services for specific Internet
application data flows. RSVP was initially developed by the University
of Southern California Information Sciences Institute and the Xerox
Palo Alto Research Center. The RSVP standards effort is being run by
the IETF. RSVP provides three transport service levels: best-effort,
rate-sensitive, and delay-sensitive. Transport is provided using RSVP
tunnel interfaces, which are established between the gateways in the
transport path between sending and receiving hosts, utilizing IP
multicast and the Internet Group Membership Protocol (IGMP). For
more information on RSVP, refer to the IETF Web site
(http://www.ietf.org).
ATM Switch Architecture
ATM and LAN switch architecture are essentially the same. From an
operational perspective, there are some big differences, because the
ATM transport mechanism is so functionally different from traditional
Layer 2 LAN and WAN transmission protocols. In Chapter 5's overview
of the ATM protocol, the distinction between public and private ATM
switches was introduced. The difference between them is that private
ATM switches are used to provide ATM transport between privately
managed and connected ATM switches, whereas public ATM switches
are maintained and operated by a public network service provider,
such as an Incumbent Local Exchange Carrier (ILEC) or
Interexchange Carrier (IXC) which provides public ATM network
access along the same lines as Transport-1 and ISDN carrier service.
This discussion focuses on private ATM switch architectures and
features, because these switches are constructed specifically to
provide ATM capabilities. Although functionally the same, public ATM
service providers generally do not utilize application-specific switches.
Instead, a general-purpose telecom carrier-class switch is used,
which utilizes application-specific interface modules and software
modules to perform specific tasks.