Proximus Forum 500 Series, Руководство по монтажу и пусконаладке

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Point-to-Point Connection Technology
PBX Networking 229
Example of a PBX network
Various line types and transmission protocols can be used for point-to-point
connections. The required network topology (distance, connection capacity)
determines which type of point-to-point connection is most suitable.
An IP network connection with Q.SIG-IP or SIP tie line can be established
either with a direct LAN connection or via a fast VPN connection. Q.SIG-IP or
SIP tie line cannot be operated using a connection with NAT. When the
connection is via VPN, encryption is advisable for security reasons.
Point-to-Point Connection
Technology
Protocol: Q.SIG or DSS1
The Q.SIG protocol, designed for ISDN point-to-point connections, is the
preferable choice as the transmission protocol; alternatively, the DSS1
protocol, designed for ISDN dial-up connections in the Euro-ISDN, can be
used. Certain PBX networking features can only be used with the Q.SIG
protocol, however. In particular, the connection designation as internal or
external call and also the name of the caller cannot be transmitted via the
DSS1 protocol.
Both protocols implement communication on several protocol layers:
● L1: Layer 1 defines the physical line properties and the electrical coding of
signals.
● L2: Layer 2 enables communication via individual error-protected channels
that are independent of each other.
● L3: Layer 3 defines the administration of the individual channels and
implements the features designed for ISDN.
Point-to-point
connection
Trunk line
PBX PBX PBX PBX
PBX