User`s guide

2 XSR User’s Guide
Chapter 1
Overview
 Serial Interface - The XSR’s NIM serial interface typically supports
protocols such as PPP. The serial interface provides both
asynchronous and synchronous protocol support.
 PPP (WAN) -The Point-to-Point Protocol (PPP) provides a standard
method for transporting multi-protocol datagrams over point-to-
point links. PPP defines procedures for the assignment and
management of network addresses, asynchronous and synchronous
encapsulation, link configuration, link quality testing, network
protocol multiplexing, error detection, and option negotiation for
such capabilities as network-layer address negotiation and data-
compression negotiation. Also supported: PPPoE Client and sub-
interface monitoring, and Multilink PPP protocols as well as Dial on
Demand (DoD) and Bandwidth on Demand (BoD).
 IP Protocol - IP supports interconnected systems of packet-switched
computer communication networks. It uses a 32-bit addressing
scheme where an IP address is represented by four fields, each
containing 8-bit numbers. Also supported: secondary IP addressing.
 DHCP Server - The XSR supports DHCP Server on the trusted LAN to
provide IP addresses to computers on a customer's private LAN
segment.
 Network Address Translation (NAT) and Port Address Translation
(PAT); Automatic NAT transversal extension enables VPN traffic to
connect through ISP or service provider network.
 IP Routing - The XSR supports RIP and OSPF dynamic routing, a vital
function of the IP protocol. Stored in a routing table, routing
information is used by the XSR to determine the route for each packet
passing through the router. VRRP is also supported for default router
redundancy and load balancing.
 Frame Relay - The XSR provides this fast-packet switching method for
wide-area networking. Acting as a DTE, the router encapsulates data
in a frame and transmits that data while serving as a source device.
When it is a destination device, it receives frames and de-
encapsulates them. The XSR’s implementation of Frame Relay
employs the User Network Interface (UNI) for PVC (DLCI)
connections with Committed Information Rate (CIR) traffic shaping
and BECN congestion control.