Innovaphone IP1200, Руководство администратора

Страница: 94 / 114

Page 94 innovaphone gateway
represents the interface between application and the operating system.
PP
PP ( P ortable P art) is used as a synonym for a cordless telephone (handset).
PPP
The PPP protocol ( P oint-to- P oint P rotocol) is conceived as the protocol for
dialling into the Internet over line-switched networks. The PPP protocol
allows data transmission over synchronous and asynchronous switched and
dedicated lines. Consequently, it is capable of operating independently of
the respective physical interface. The only prerequisite for using the PPP
protocol is a fully transparent, fully duplex data line.
PPPOE
PPPoE ( P oint-to- P oint P rotocol o ver E thernet) is the use of the PPP network
protocol ( P oint-to- P oint P rotocol) over an Ethernet connection.
PPTP
The PPTP ( P oint-to- P oint T unneling P rotocol) is a protocol developed by a
vendor consortium (Ascend Communications, Microsoft Corporation, 3Com,
inter alia) for the creation of a VPN (
V irtual P rivate N etwork). It allows the
PPP ( P oint-to- P oint P rotocol) to be tunnelled through an IP network; the
individual PPP packets, in turn, are encapsulated in GRE packets ( G eneric
R outing E ncapsulation). To secure the data transfer, PPTP has a 40-bit or
128-bit RC4 algorithm ( R ivest C ipher).
PRI
PRI ( P rimary R ate I nterface) is the access provided for medium to large
private branch exchanges, and offers much higher transfer speeds
compared with the basic access. It allows subscriber equipment to be
connected to the ISDN local exchange. A maximum information capacity of
30 basic channels each at 64 kbit/s, as well as a D channel with a capacity of
64 kbit/s are available to the end-user via the S2M interface.
Q
QOS
QoS ( Q uality o f S ervice) refers to all procedures that influence the data flow
in LANs ( L ocal A rea N etworks) and WANs ( W ide A rea N etworks) so that the