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Chapter 2. Technology Overview
TBOP
PPP
Link Control Protocol
Network Control Protocols
2-8
Transparent Bit Oriented Protocol (TBOP) is an ADTRAN-proprietary
protocol that is used to transmit HDLC-formatted traffic across the frame
relay network. TBOP allows the transportation of protocols "unknown" to
ATLAS to be encapsulated in frame relay and sent to a remote location via
frame relay. This protocol can be useful in transporting other vendors'
proprietary protocols across the WAN.
ATLAS accepts HDLC-formatted data on one of the V.35 or T1 ports and
forwards that data across a frame relay network to another ATLAS or an
ADTRAN frame relay device (for instance, if ATLAS is communicating with
an IQ product).
The Point-to-Point Protocol, PPP, is the Internet standard for the transmis-
sion of IP packets over serial lines. PPP is not confined to serial links though;
it runs on async or sync lines. PPP is also a multi-protocol transport mecha-
nism. This means that PPP transports several different types of other proto-
cols: IP, IPX, Appletalk, Bridged Ethernet, etc. All of these protocols can be
transported at the same time. There are various compression protocols to in-
crease the transmission rate of the link. The ATLAS only supports the IP
protocol over dedicated links. As per RFC 1661, PPP comprises three main
components:
1.
A method for encapsulating multi-protocol datagrams.
2.
A Link Control Protocol (LCP) for establishing, configuring, and testing
the data-link connection.
3.
A family of Network Control Protocols (NCPs) for establishing and
configuring different network-layer protocols (such as IP).
To be portable to a wide variety of environments, PPP provides an LCP. The
LCP is used to automatically agree upon the encapsulation format options,
handle varying limits on sizes of packets, detect a looped-back link and oth-
er common misconfiguration errors, and terminate the link. Other optional
facilities provided are authentication of the identity of its peer on the link,
and determination of when a link is functioning properly and when it is fail-
ing.
Point-to-Point links tend to exacerbate many problems with the current
family of network protocols. For instance, assignment and management of
IP addresses, which is a problem even in LAN environments, is especially
difficult over circuit-switched point-to-point links (such as dial-up modem
servers). These problems are handled by a family of NCPs, and each manage
the specific needs required by their respective network-layer protocols.
ATLAS Frame Relay User Manual
61200263L1-1.1
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