Lancom Systems LCOS 3.50 - Manual (Page 92)

LANCOM Reference Manual LCOS 3.50 ̈ Chapter 7: Routing and WAN connections
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Routing and
W
A
N
con
n
ections
of routers made by different manufacturers since this protocol is supported by
practically all manufacturers.
Due to the increasing importance of this protocol family and the fact that PPP
is not associated with any specific operating mode of the routers, we will be
introducing the functions of the devices associated with the PPP here in a sep-
arate section.
7.6.1 The protocol
What is PPP?
The point-to-point protocol was developed specifically for network connec-
tions via serial channels and has asserted itself as the standard for connec-
tions between routers. It implements the following functions:
̈ Password protection according to PAP, CHAP or MS CHAP
̈ Callback functions
̈ Negotiation of the network protocol to be used over the connection
established (IP or IPX, for example). Included in this are any parameters
necessary for these protocols, for example IP addresses. This process is
carried out using IPCP (IP Control Protocol).
̈ Verification of the connection through the LCP (Link Control Protocol)
̈ Combining several ISDN channels (MultiLink PPP)
PPP is the standard used by router connections for communication between
devices or the WAN connection software of different manufacturers. Connec-
tion parameters are negotiated and a common denominator is agreed using
standardized control protocols (e.g. LCP, IPCP, CCP) which are contained in
PPP, in order to ensure successful data transfer where possible.
What is PPP used for?
It is best to use the point-to-point protocol in the following applications:
̈ for reasons of compatibility when communicating with external routers,
for example
̈ remote access from remote workstations with ISDN cards
̈ Internet access (when sending addresses)
The PPP which is implemented by LANCOM can be used synchronously or
asynchronously not only via a transparent HDLC connection, but also via an
X.75 connection.