Softswitch Network Topology; Softswitch Call Flow - Alcatel-Lucent 7302 Information Manual

5 — VoIP overview
Server (s) DHCP,
application, FTP etc.,
IP phone
PSTN
gateway
PSTN
cloud
POTS
phone
Class 5 PSTN
switch
The ONT supports redundant softswitch servers. When operating in a redundant
configuration, the ONT contacts the secondary server if the primary server is lost.

Softswitch call flow

The call flow associated with a conventional softswitch for traffic originating from
the ONT is generally the same as specified in the IETF/ITU-T H.248/Megaco call
flow.
One fundamental difference between the gateway mode and the softswitch mode is
that, in the softswitch mode, the Megaco signaling protocol instructs the ONT in
terms of playing tones, and on-hook and off-hook event through out-of-band
signaling messages.
5-8 November 2013
Figure 5-2 Softswitch network topology
Management channel
Softswitch
IP cloud
BRAS
L2
Ethernet
cloud
Note —
To implement redundant softswitch servers, you must use the
DHCP option 120 for a second softswitch IP address.
Alcatel-Lucent 7302 ISAM | 7330 ISAM FTTN | 7360 ISAM FX ONT R04.06.02
Signaling
channel
RJ45
ONT
OLT
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POTS
phone
IP
phone
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