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Voice over IP Revealed
A. ... 1 VOICE OVER FRAME RELAY (VOFR). ... 2 VOICE OVER ATM (VOATM). ... 21
DRAWBACKS OF VOICE OVER IP. ... Executive Summary
The objective of this paper is to present a detailed insight on Voice over IP. ...
Although there are many variations to implementing a Voice over IP solution, the type of implementation is
dependent on the company environment. ... Both PSTN and VoIP need
investment in the infrastructure, so the company should focus their investment on VoIP to combine their voice and
data networks. ...
Companies that already have a PBX infrastructure in place should implement an IP PBX Converged solution as it
takes advantage of the existing PBX investment while still being able to take advantage of new services offered
through VoIP. ...
In order to help decision makers make well-inform decisions in regards to voice telephony, we also identify two
other alternative technologies - Voice over Frame Relay and Voice over ATM. ...
Voice over IP is an attractive telephony network solution primarily because it lowers cost and increases the
flexibility of the network. In particular, VoIP lowers hardware and support costs as it merges what would have
been separate voice and data networks into one single network. ... This can be especially advantageous in Wide Area Network
setups, replacing more costly dedicated ISDN setups between multiple offices with IP systems. ... A fully IP based data and voice communications network enables
agencies to consider time and cost management applications such as IP conferencing, IP faxing and unified
messaging, with reduced overhead cost for implementing each. Some of these additional features not available
in typical PSTN networks are listed below:
Internet Telephony
LAN/WAN voice
communication
Fax over IP
Unified messaging
Conferencing
Advanced call
routing. ...
Voice over IP (VoIP) is the technology of sending voice information in digital form in discrete packets over the
Internet. ... The major drivers for implementing VoIP are the cost savings by avoiding the
charges incurred by using ordinary telephone service, the convergence of voice and data networks onto one
network, additional service features, and future expectations of application integration. ...
This is similar to Internet telephony, without the quality of service issues that hamper
voice communications over IP. ...
email, fax, and voice communications). ...
Tele and video-conferencing over IP is less expensive than ISDN connections, saving
travel time and costs. ... VoIP Infrastructure
To make use of voice over IP technology, there should be several deployments in terms of hardware and
software. ... 1 The Basic Elements of VoIP
POTS Phone
(Plain Old Telephone Service)
PSTN
IP Phone
(H. ... As shown above, main components of VoIP technology
are Gateway, Gatekeeper, Multipoint Control Unit (MCU), and Terminal such as POTS phone, IP phone, and PC. ... 323 published in 1996 by the ITU-T is a standard for multimedia communication via IP-based LANs and the
Internet, and now VoIP technology is mainly based on this standard. ...
Cisco Systems, one of the leading companies in voice communication business, provides several kinds of
gateways with different functions, different covering sizes, and different prices. ...
The Cisco ATA 186 Analog Telephone Adaptor is a handset-to-Ethernet adaptor that turns traditional telephone
devices into IP devices. Customers can take advantage of the many IP telephony applications by connecting their
analog devices to Cisco ATA. ... 323
Cisco ATA 186-I2
Cisco ATA 186 deployment example
Page 6 To make Voice over IP work, we need three roles: Gateways, Switches, and Routers. ...
Plain Old Telephone Service (POTS) phone
IP phone
PC
Even though people mostly use POTS phones, regardless of our intention, we could use VoIP technology. ... Currently 20 to 30% of international calls are over IP.
More direct use of VoIP technology is conducted by IP phones and PCs. IP phones are now mainly deployed to
companies and are especially used for cost reduction and addition of extra phone services. ...
Currently many kinds of IP phones are provided by the major technology companies. A couple of IP phones by
Cisco Systems are as follows. ...
Cisco IP Phone 7905G
192x64 pixel, monochrome display
4 soft keys
Line/local power
1 RJ-45
Single line
Around $250.00
Page 8 Cisco IP Conference Station 7935
Certainly, the price is based on what functionalities are added into each of the phones. If not using VoIP
technology through IP phones as above, but instead through a PC that includes a microphone and speaker, the
user doesnt need to buy anything. If the PC doesnt have microphone, then user just needs to buy a headset,
which is much cheaper than IP phones devices. ... 00
Cisco IP Phone 7940G
145X100 pixel, grayscale display
4 soft keys
2 programmable line keys
High quality speaker phone
Line/local power
2-port Ethernet switch
XML applications
Around $410 00
DSP100 VoIP USB Monaural Headset
Digitally enhanced USB headset for VoIP
applications and speech recognition
Inline digital control for mute & volume with
LED
Digital Signal Processor
Around $65. ... VoIP Software
Voice over IP is made possible through the use of software. ... These products have to digitize voice, compress it, turn it into packets for
sending, and then at the other end it has to be decompressed and returned to a form as close to the original as
possible. ... 1 Configuration Possibilities
We can use multiple types of gateways to turn voice into IP packets. ... 2 Transport Protocol
The real time transport protocol (RTP) is currently in widespread use for real time voice applications. ... It was specifically designed to transport
PSTN messages over IP networks. ...
Voice over IP (VoIP) rates have become competitive with traditional PBX rates in recent years, thus making the
decision to elect VoIP solutions is more appealing since it allows for a range of new services. ...
VoIP provides additional services such as the capability for a single inbox for e-mail and voicemail, easy call
transfer around the country, user-controlled feature changes, fax over IP, and simple remote systems
management. ...
Ports required
Costs of long
distance
Entry level cost
Addition of
additional switch
Voice and data
networks
Features and
services
Equipment
features
Flexibility
VoIP (packet switched)
Requires 1 telephony port while sharing
common IP interface
Requires 2 ports per call (one on
receiving side, one on sending side)
Scalable to suit a variety of network
sizes
Requires switch to be connected to IP
cloud once
PBX (circuit switched)
Requires 2 ports per switch (incoming
and outgoing)
Depending on distance, call may need to
go through several switches (regional,
national, international on both sides), as
well ending destination
Requires high traffic volume to achieve
reasonable return on investment
Requires switch to be interconnected to
several other switches, thus increasing
transportation costs as well deployment
time
Requires separate networks for voice Enables both voice and data to utilize
same network, thus reducing operational and data, and consequently each
costs network has to be managed separately
Supports open standards and promotes Relies on switch service providers to
competition between vendors, thus is develop new features and services
simple and cost-effective to expand
features and services
Includes many additional features such Additional features need to purchased
as ability to compress data at no separately such as compression
additional cost thus maximizing components thus incurring cost to
bandwidth and reducing operating costs maximize bandwidth
Inherent nature of technology allows for Inherent nature of technology requires
quick set-up and rerouting of switches to significant time to plan set-up and
quickly adapt to market rerouting of switches
Page 12 According to the Multiclient Study done by www. ... com in January 2000, IT managers expect to realize
savings from Voice over IP in the following areas:
VoIP is best suited for companies that have many remote locations or companies that have many telecommuters
and remote workers. As evidenced by the chart below, the more users in various locations, the greater the
benefit of Voice over IP. ... )
2500 2000 0
Large companies benefit from VoIP
1500 1000
Break-Even Point =
5 Sites, 200 Users
500
Number of Users
PBX VoIP
Page 13 VoIP
Data Switch Port
IP Telephones
Copper Wires
Gateway (24 ports)
Internet Connection
PBX
VoIP cheaper than PBX ports
Less expensive than IP
$75-100/port
More expensive than analog
Not needed Typically needed
$3,120 Not needed
$40/month DSL or Cable, $600 full Not needed
T1
Costs involved with implementing Voice over IP
IP PBX
IP Phones
LAN
C V I S
M
A
P100
Voice
Gateway
Analog/Digital Phones
F.
Approximate Word count = 6937
Approximate Pages = 27.7
(250 words per page double spaced)
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