Calling line identity(caller id)


Although i feel it may not be related with asterisk but still posting for hope.
Problem is if i want to call to a pstn no from voip service or phone i dont see the caller id . I can see it if i call to another sip device or softphone.
My question is what configuration left to be done?
In sip.conf under user context there should be callerid=<> whatever number i give right? Well there must be some authentication when voip to pstn swicthing of this coming phone no it must be done by the provider who is switching this right?

Let explain the scenario details. i have my incoming did for my hard phone.
now in hard phone configuration caller id enable feature, send caller id,
name (which will show as caller id ) field is filled out i mean everything is done what need to be done. Now i route for my outgoing call by another provider who terminate it far end dont know how are they switching to pstn but they said they can. But still coimg as unknown number.
Can any one give any idea?


Most PSTN providers will either force a fixed CLI, or require that the CLI be within the number range that they have allocated to you.

To elaborate on above. You can only send out a CLI that belongs to you. In other words, either the main bearer number or one of your DDI range. This is to stop fraud.

Imagine if you could send out a number that isn’t yours. Oh the fun to be had :smile:.

Just a little more. Is that DID have to be with that provider who is
terminating to pstn? I mean my DID is provided by some company now
outbound call is provided by another one .If we want to show the did
in pstn phone does those service have to be from same company?

The DDI (DID) belongs to the trunk. You can not present a CLI of one trunk on another.


Most suppliers of IP trunks will allow the setting of a CLI number that belongs to you, It doesnt need to even be a number supplied by them, All my Customers who have ISDN in and IP out set the CLI as their ISDN number. There are rules to be observed but its perfectly legal and possible.

There are suppliers that will let you set any CLI you want, I wont say who as they are meant for wholesale use.

The rules also vary on weather your systems is considered a termination or transit switch, as a transit switch is allowed to transmit on the CLI it receives.

In the end what the IP trunk supplier allows is up to them. Some are lax some are very strict.