Take a look at it below:
This part of the dial plan is rather straight forward, it deals with three digit numbers such as 101, 123, 200 and 999 to list but a few. Some of the strings have S3 on the end while 999 has S0. The reason for this is simple, S3 will tell the device to wait three seconds before matching any numbers entered against that dialplan string which gives the user time to enter further digits which may be needed to dial longer numbers.
An example, you may want to dial 123, if we have 123S0 in the dialplan then this will allow you to do that and upon pressing the number 3 the phone gets a match and dials the number immediately however should you need to dial 123456 then you would be unable to do so because once you get to the point where you entered third digit it would have matched the numbers entered against the 123S0 string and dialled that number.
S0 at the ends tells the device to dial the number without delay.
This part of the dialplan string matches four digit numbers such as 1471 and 1571. The first number must be a 1, the second number can be a 4 or a 5, the third must be a 7 and the fourth can be any number between a 1 and 9. Again S0 at the ends tells the device to dial the number without delay.
This allows calls to helpline numbers such as 116 006 or directory enquiries such as 118 118. The x's represents a number from 0-9 so instead of me having individual dialplan strings for each number beginning with 118 and there are loads here in the UK (e.g. 118 555 or 118 888) in my dial plan the x's allow me to use one string to match several numbers beginning with 118 otherwise my dial plan would be oh so longgggggggggggggg!
If you were to dial a number starting with 09 and you have the above string in your dial plan the the call will be terminated immediately, this is great for preventing calls to premium rate numbers. (The ! part of the string tells the phone not to continue with the call.)
This part of the dial plan refers to international calls, as international numbers vary in length there is no easy way to create a string for them unless you create individual strings for each country code and the problem there is your dial plan would be so longgggggggggggggg. By now you should understand what the string does up until the full stop at the end, the full stop simply allows more time to input numbers. As mentioned above, because international numbers vary in length you cannot create a fixed string of say eleven digits for all international calls otherwise should you attempt to call a number of lets say fifteen digits in length, your device would have started to call out on the eleventh digit.
As above however allows you to add a prefix such as 141 or 1470 when dialling international numbers. 141 hides your number, 1470 shows your number.
When you dial a local area phone number from BT landlines you only need to dial the phone number, you don't need to include the area code like you do on mobile phones. Sadly just like mobile phones when calling out on Cisco, Linksys, Sipura and as far as I am aware all other VoIP phones and adaptors you need to enter your area code first when dialling a local phone number.
The above string will automatically add your local area code to every local call you make. 01792 is the local area code for Swansea, my home town. All you need to do is change the 01792 part of the string to your area code, if your area code is 0121 then you simply change it to look like this: <:0121>[2-8]xxxxxS0
Any six digit numbers you dial starting with a 2, 3, 4, 5, 6, 7 or 8 will start to ring immediately. If you dial 456456 the phone will actually call 01792456456. You need to make sure your dial plan does not contain any other strings that may interfere with calling local numbers, e.g. if I had the following string in my dial plan 456S0 then I wouldn't be able to call local numbers beginning with 456 as it would dial out early not allowing me time to enter the final three digits.
An easy one, refers to UK national numbers and numbers like 0800, 0870, 0871 etc...
As above however allows you to add a prefix such as 141 or 1470 when dialling national/mobile numbers. 141 hides your number, 1470 shows your number.
This is solely used in my dial plan to allow calls to other users who use my VoIP provider Voipfone.
Again this string is unique to Voipfone, example: dialling **201 allows you to pick up extension 201 when it is receiving an incoming call from another phone.
The last part is used to identify short codes, you know numbers like *36 usually used to turn on a service or deactivate one.
A dial plan always starts with a ( and ends with an ) the | symbol located in the above dial plan is used to separate each dial plan command.
For a more information about dial plans and how to create one yourself see here: http://www.netphonedirectory.com/pap2_dialplan.htm