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VOIP Speech Network
Solution of Public Securities System
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System Overview |
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Public securities (politics & laws) communication network is the
important technology means of command and control for the public
securities system. At present, provincial and municipal network
Grade I of speech communication have been initially formed based
on the circuit switching; while network Grade III and IV
covering district branch bureaus and police stations are
generally far from completion. Yet, with the strategy policy of
“Technology to strengthen the police” issued by the State
Council, “Golden Shield Engineer” focusing on public securities
informatization has got high attention of all leaders.
So the informatization of public securities system is speeded up
and IP technology is becoming popular and well applied. Since
not many staff working in the district bureaus and police
stations, and the organs are loose to some extent, so the cost
will be high if employed traditional circuit switching and also
the maintenance will cost much labor. Therefore, by the time
when constructing Grade III & IV IP data network of public
securities system, IP phone system should be established for
“Three networks in one”, which will help improve the data
utilization, lower the construction cost of speech communication
system and also shorten the construction period. And IP phone
special network is also the effective means of improving
internal communication securities.
System application solution
For the speech communication system based on traditional circuit
switching, communication between inferior nodes requires
exchange in superior nodes. The transmission equipments should
be used in pairs, and the capacity of central equipments circuit
should be large enough. While two nodes of IP speech equipments
can realize direct communication without central speech
equipments whose utilization of transmission network and
transmission broadband is very high, with lowered central
equipments load and small investment in central nodes.
Public securities network Grade III & IV should cover the public
stations in wide area and large quantity. If to adopt the speech
transmission based on the traditional circuit switching, the
grass-roots organs should enlarge the equipments of central
nodes with higher cost, longer construction period and worse
flexibility since there is no selection for flexible small
terminal communication equipments.
Yet, IP phone communication system can fully play use of current
IP data network for speech communication without special speech
communication network. The IP phone terminal equipments with
features of simplicity and flexibility are not only suitable for
small organs but also advantageous in low construction cost,
short period, “Plug-and-Play” of equipments and simple
maintenance.
Chart of public securities network Grade IV VOIP system
The typical application is to configure one digital relay IP
speech gateway in the urban or county central organs to connect
with IP network and original program-control phone system. And
then the grass-roots organs in rural and town respectively
configure one IP speech gateway with small channels, which will
help the original phone communication system to cover all basic
organs through IP phone network. By the time, one IP phone
network management system (CMC Call Management and Control
Center) in central organ should be established for the central
organs to unitedly carry out the management and control of
number collocation, equipment network management and call
statistics.
Solution features:
With function of “One phone for two numbers”, enable to share
PSTN urban call and VOIP special call network in common
Dial to automatically call the router, i.e., connected to PSTN
when the user is dialing an urban number and connected to IP
network when dialing a special number.
When IP data network fails, the call can automatically switch to
PSTN urban call network, and IP gateway will release an alarm.
In support of IP phone meeting system.
In support of normal communication within fire wall of public
securities data network.
In support of confidential fax.
In support of VOIP application in all complex network
circumstances, good adjustment to network sources which is most
suitable for the group network of SDH, DDN, FR, wireless network
bridge, satellite communication, VPN and Internet access.
System components:
(1) Nodes of urban and county bureau network Grade II & III
Digital relay IP speech gateway
The central organ is strongly recommended to configure one
CNG8000 digital relay IP speech gateway to connect with original
program-control phone exchanger through E1 digital relay
circuit, for realizing the interconnection and extension of
communication network. CNG-8000 IP speech gateway will provide
1-16E1 digital relay; support Chinese and ITU-TH.323V3/4
standard; support China No. 1 /ISDN PRI signaling.
CMC Call and Manage Control Center System
The system includes gatekeeper module, call statistics module
and network management module.
The gatekeeper module is responsible of caller identification,
port number distribution, No. sources management, call router
management and broadband management of the whole VOIP phone
network system.
The call statistics module is in charge of call statistics,
charge, formation and enquiry of calling list of the whole IP
phone numbers.
The network management module takes the responsibility of
terminal equipments remote management setting, software
upgrading, performance monitoring, failure alarming, system
daily recording and network topology of IP phone network.
(2) Four levels organs of section, station, team, etc.
CNG 2000/3000 IP speech gateway: Based on module
multi-functional IP phone gateway equipments, with 2-16 channels
users’ relay port (FXS), or ring relay (FXO) for use in county,
district bureaus or larger organs with Level IV.
CNG 1000 IP speech gateway: small-size IP speech gateway with
2-4 channels users’ relay port (FXS), or ring relay (FXO) for
use in medium-size or small-size organs such as public stations.
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