Function Summary - Extreme Networks PoS Installation And User Manual

About the PoS Modules

Function Summary

The following sections provide brief descriptions of the key functions provided by the
PoS modules. Each of these sections is expanded into greater detail in Chapter 3.
SONET and SDH
SONET and SDH are the two terms used to identify a time division multiplexing
technology that is optimized for transporting voice traffic across a digital optical
network, but that is also capable of providing high-speed capacity for transporting data.
The term SONET is used to identify the technology used within the North American
digital network. Its standards are published by Bellcore and the American National
Standards Institute (ANSI). The term SDH is used to identify the equivalent standard
approved by the International Telecommunication Union (ITU) for use in Europe and
elsewhere in the global digital network. Because SDH evolved out of SONET, the two
standards are closely joined and have been widely accepted as a dominant choice for
implementations requiring high transport capacity and resistance to failure.
PPP
PPP encompasses a suite of protocols designed to provide standard methods for
transporting datagrams over point-to-point links. The use of PPP over SONET links is
commonly referred to as Packet over SONET, or PoS. The Extreme Networks
implementation of PPP for the PoS module provides support for the following protocols
in the PPP suite:
• Link Control Protocol (LCP)
• Link Quality Report (LQR) Protocol
• Challenge Handshake Authentication Protocol (CHAP)
• Password Authentication Protocol (PAP)
• IP Control Protocol (IPCP)
• Bridging Control Protocol (BCP)
• Extreme Discovery Protocol Control Protocol (EDPCP)
MPLS
The PoS module ports provide MPLS support via a PPP link. The MPLS Control
Protocol (MPLSCP) allows MPLS labeled packets to be transported across a PPP link.
Packet Over SONET Module Installation and User Guide 1-9