Dialogic D/300 JCT-E1 is the entry level board for anyone who needs digital network interface with PSTN network as well as voice resources in the single board. I feel, D/300 board is most used entry

Dialogic D/300 JCT-E1 board

Features of Dialogic D/300 JCT-E1 board

1. Digital Network Interface

It has both E1(2.048MBPS) and T1(1.544 Mbps) support. It supports digital interface network protocols like ISDN PRI, R2MF. ISDN PRI is widely used protocol for connecting CTI board with PBX systems. With D/300 board, it is quite easy to configure it to work with many ISDN variants as per PBX from one country to another or manufacturer.

2. FAX support

Dialogic D/300 board supports both FAX and host based speech recognition. In certain cases, FAX and speech recognition may not work together. It also supports CSP ( Continuous Speech Processing) which offers IVR developers a powerful feature to develop many interesting IVR applications and features depending on the call progress. Speech recognition feature provides IVR developers to develop Speech-Enabled menu for any IVR application.

3. Scalability

Dialogic D/300 supports H.100 connector and it allows it to connect to other Dialogic boards. Inexpensive normal PC can be used to install this board and one PC may install upto 16 boards per machine if PCI slots are available.
With its support for GSM and G.726 bit exact voice coders ( standard for Voice Profile for Internet Messaging (VPIM) , one may develop unified messaging solutions based on D/300 board.

4. Programming

Dialogic D/300 board is supported by many RAD Tools for IVR development. It also supports widely popular GC ( Global Call Protocol) for making many high end, mission critical IVR applications.

Applications

D/300 board can be used to develop any kind of IVR applications. It offers many call related information available with digital network interface protocols. Call bridging available in ISDN PRI is one of the feature which is used to make Click To Call application can be developed.

D/300 board is also ideal choice for starting a voice portal service to start with 30 lines and then increase the lines.

DIalogic has some other models with higher capacity with same features. D/600 and DMV1200 have 60 voice and 120 resources respectively. One may move from D/300 to DMV/1200 without having to make any changes in the application.

Other CTI vendors like Donjin, Synway, Digium too have D/300 equivalent boards. For example, Digium TE122P/TE122B, Synway TEJ Series and Donjin DN300 are Dialogic D/300 equivalent boards with similar features.

I think, analog CTI boards most problematic to configure other than simple incoming or inbound IVR Software. They are dependent on switch or PBX connected to them for many basic IVR functions, call operations. I am trying to list here the problems I had been facing while using analog CTI boards:-

1. Disconnect
2. Dial Tone
3. Dial out
4. Caller Id

1. Disconnect
You need to ‘define’ the disconnect tone to your IVR application so that it can detect disconnect. This disconnect tone may vary from PBX to PBX. Dialogic has a tool PBXpert to detect various analog tones like dial tone, disconnect tone, busy tone, ring back tone etc. With CRBT ( Caller Ring Back Tone) being popular now a days, detection of ring back tone has just become more difficult.

2. Dial Tone
Dial tone also varies from one PBX manufacturer to another. This dial tone becomes very important when you make an outgoing call. IVR application may be unable to make outgoing call if it fails to detect dial tone. Though there are ways to dial out without detecting dial tone or learn dial tone and feed in IVR application, it is still not easy.

3. Dial out
Once successfully dial out, it may not be easy to detect if dialled party has picked up the call. Many people use Call Progress Analysis to detect, if person has picked up the call. But I always think, it is not easy or it does not work accurately all the time.

4. Caller ID
Unlike in digital CTI boards or Digital Telephony interface, caller ID detection is almost a pain and it may not work accurately all the time. Normally, in analog interface with PBX, the caller id is sent by PBX in DTMF form after first or second ring. So, it is really cumbersome to detect Caller ID.

Digital CTI boards with digital interface does not have the above problems. So it would be nice if one can avoid using analog CT boards and use digital boards. Though digital boards are costlier, but now a days there are many CTI vendors which have digital CTI boards which are priced very competitive.

I have thought of an arrangement to avoid using analog CTI cards. Though it may make the IVR system costlier, but most probably, it will be good arrangement in terms of future enhancements, more features. My thinking is to use use a EPABX with PRI card. the CTI board will be connected to EPABX through E1 connectivity and use ISDN PRI protocol. Commonly used and widely available. In turn EPABX may have CO lines from telephone service provider ( analog lines which other wise you wold have connected to CTI board directly). This kind of EPABX may cost less than Rs. 150,000/-

Now, when price of 4 port CTI boards starts with Rs. 10,000/-, investing another Rs. 150,000 on a EPABX and another Rs. 30,000 for a digital CTI board, may not make sense, honestly! But there are some benefit of using this kind of arrangement for for specific IVR application and outbound IVRS is one of them, considering the cost of hiring a E1 link from telephone service provider.

But, the problems I have listed above can be solved by smartly writing your IVR software. In fact, they must be routine problems for many IVR developer, unfortunately no document is available on net, at least I could not Google it. And I am yet to write a smart IVR application for analog CTI board as I started my IVR software development with Dialogic D300 board and R2MF protocol!