Rfc 1490 - Nortel Passport 4400 Series Introduction Manual

Concepts and Applications Passport 4400 Introduction and Road Map

RFC 1490

The Passport 4400 supports RFC 1490 frame relay Direct Connect. This means
that it interoperates with third-party routers directly off of the frame relay
cloud. Third-party routers may also be connected to the Passport 4400 through
their own frame relay ports.
LAN traffic from a local Passport 4400 is transmitted over the frame relay
network directly to a router. Support connections to the Internet are made via
RFC 1490 encapsulation (see figure below).
Passport 4400 Router
Frame
Passport 4400
Relay
Internet
RFC 1490 PVC:
PANL PVC:
Passport 4400 supports LAN connectivity to a remote router connected behind
a Passport 4400. Traffic is transmitted over the link using RFC 1490 encapsu-
lation (see figure below).
Passport 4400
Passport 4400
RFC 1490
RFC 1490
PVC
PVC
Frame
Router
Relay
PANL PANL
PVC PVC
Combining the two previous applications, LAN traffic is carried between the
Passport 4400's internal router, the Internet, and a third-party router connected
to a Passport 4400 via its frame relay DCE connection. Typically, a customer
will already have a router-based network. The third-party router can also act
as an Internet gateway. In this capacity, the router can accept all Internet-bound
traffic, then send smaller data packets to Passport 4400 nodes to help ensure
voice quality of service (see figure on page 1-16).
1-15