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D-Link DPH-70L IP Phone

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PCQ Bureau
New Update

This newly launched IP phone from D-Link allows you to make ISD calls, at far

cheaper rates than the regular PSTN networks. Earlier, this used



to be achieved from a computer via software like Net2Phone, but now you're no
longer dependant on a computer for the job. It doubles as a regular PSTN phone

and is quite easy to set up. You just need a dial-up ISP connection and a VoIP

calling account (calling card coupon). Using its menu button, you can configure

the dial-up Internet account and calling card details in the phone (we received

a Rs 500 calling card coupon from IPYantra for testing this phone). To start the

call, dial your ISP by pressing VoIP button. Once connected, it appears in VoIP

mode. 

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You can now start making international calls. The LCD display shows the

status of your calls. The phone offers hands free operation with an adjustable

speaker and ringer volume control. In addition, it has silence suppression,

voice activity detection and comfort noise generation features, which ensure

voice quality at both ends. 



Price:
Rs 7,150 (1yr warranty)


Meant For:


International callers


Key Specs:


Supports H.323 and SIP protocol, uses V.34 Modem interface using V.90 Data pump. For voice compression the unit uses G.723.1, G.729A/AB compression


Pros:


Can make VoIP and PSTN calls from the same device


Cons:


When dialing a PSTN number, you need to press Enter to initiate dialing, else wait for 10 seconds


Contact:


D-Link India, MumbaiTel: 26526696, E-mail: sales@dlink.co.in  

It supports both H.323 and SIP protocols. Plus, it uses a V.34 Modem

interface using V.90 Data pump. For voice compression, the unit uses G.723.1 and

G.729A/AB compression. These are the latest compression technologies being used

for VoIP based communication.

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Performance and call pricing



We tested this device by calling the US, the UK and Singapore and checked for
distortion, echo, quality of voice and delay. We also compared the cost of VoIP

calls with those made from PSTN networks. The PSTN networks used were those of

BSNL and Airtel. We found that calls made from the VoIP and Airtel networks were

much cheaper than BSNL (see table), but qualitywise the BSNL network performed

better. In VoIP calls, there were some nagging quality related issues. For

example, when we made calls to the UK, there was distortion, echo and delay in

voice quality.

To confirm this, we made calls of the same duration from a PSTN network, and

found it to be free of these problems. The same thing happened when we made

calls to Singapore. However, calls to the US, gave us good voice quality across

both VoIP and PSTN networks. To cross check, we did the same test three to four

times and every time we got a different performance. VoIP calls are therefore,

totally dependant on your Internet connectivity. Because of the dial-up

connection, you never know the speed at which you will be connected to the ISP.

Bottom Line: This is a good option if you need to make lots of casual

or quick phone calls abroad. It's not suitable nor is it meant for business

users, as its quality is not as reliable as that of a PSTN based network.

Call comparison across VoIP and PSTN networks
   

Calling cost

(Rs)

VoIP quality

Country   

Duration   

VoIP    BSNL    Airtel    Voice

quality   
Distortion    Echo    Delay
US    00:01:00     1.9    48    7.20    Good    Yes    No    No
US    00:00:24   

1   
 18     3     Good     Yes     No     No
US    00:08:48   

17   
 396     85     Good     No     No     No
UK

(mobile)   
00:03:36    65    243    35    Good    Yes    No    No
UK

(mobile)   
00:00:18     6    21    5    Poor    Yes    Yes    Yes
Singapore    00:01:00     3    52    7.20    Good    Yes    Yes Yes
Singapore    00:01:06     3    57    7.50    Good    Not

much   
No    Yes
Internet

access*   
    20    Nil    Nil                 
Total

cost   
    116.9    835    149.90                 

Sanjay Majumder

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