Expansion Stages and System Capacity
43
Aastra 470 as of R1.2
syd-0337/1.2 – R1.2 – 11.2011
DSP modules are stacked on the call manager card and do not take up any slots for
interface cards (see
"Fitting DSP modules", page 90
). The different types of modules
can be used as a mix.
Tab. 15
DSP modules
Compared with DSP modules, modules with the designation DSPX are fitted with
more powerful DSP chips. They are used to transmit VoIP data among others using
the SRTP protocol (Secure VoIP).
Allocatable functions
One or more functions can be allocated to the individual DSP chips on the DSP
modules. For this the DSP chips have to be loaded with different firmware. The DSP
resources can be used for DECT telephony, Voice-over-IP, Voice Mail, hands-free op-
eration, integrated mobile phones or fax transmissions. This means that for each
DSP chip a specific number of voice channels is available for the corresponding
functions. Some of these functions are subject to a licence (see also
).
•
DECT
Operation of a DECT system on DSI interfaces with cordless terminals. In the case
of connections between DECT and non-DECT endpoints the voice data has to be
converted. This process requires DSP capacity. DECT channels can be used with-
out a licence.
•
VoIP
Connections between IP and non-IP endpoints are made via an IP media gate-
way. This is carry out by the integrated standard media switch that switches VoIP
channels for call connections in the IP network. The Standard Media Switch uses
DSP resources for the real-time processing of the call data. VoIP channels are al-
ways required between IP and non-IP endpoints, e. g. for internal connections
between an SIP/IP phone and a digital system phone or e. g. for an external user
who is routed to the internal Voice Mail System via an SIP network interface. In
an AIN VoIP channels are also used for call connections between the nodes (see
for an overview). The number of configurable VoIP channels depends on
Type
Number of DSP chips per module
Max. number of modules per system
SM-DSPX1
1
2
SM-DSPX2
2
SM-DSP1
1)
1)
Although no longer available, the module is still supported.
1
SM-DSP2
2