VoIP Mailing List Archives
Mailing list archives for the VoIP community |
|
| View previous topic :: View next topic |
| Author |
Message |
ben4asterisk at yahoo.com
Guest
|
 Posted: Wed May 28, 2008 12:26 am Post subject: [asterisk-users] why is CLIP(CallerID presentation) facility |
 |
|
Hello Guys,
This is not exactly an Asterisk-Users list question, but definitely have quite a few telecom/voip experts in here.
My q : Why is the Caller ID presentation facility charged? What's the big deal in providing it? Coming from the SIP/VoIP domain, all I see is setting the From(typically)/ Presentation fields, which more often than not, any self-respecting provider would set.
Is there some super-express processing need to be done somewhere along the line of the delivery of the call, for providing Caller ID?
- Ben. |
|
| Back to top |
|
 |
rj2807 at gmail.com
Guest
|
| Posted: Wed May 28, 2008 3:00 am Post subject: [asterisk-users] why is CLIP(CallerID presentation) facility |
|
|
On Wed, May 28, 2008 at 1:26 AM, Benjamin Jacob <ben4asterisk at yahoo.com> wrote:
| Quote: | My q : Why is the Caller ID presentation facility charged? What's the big deal in providing it? Coming from the SIP/VoIP domain, all I see is setting the From(typically)/ Presentation fields, which more often than not, any self-respecting provider would set.
|
Leaving aside the why-it's-charged question, I can say that in a SIP
world presenting the caller-id is not the same as presenting the
contents of the From: header to the UAS. The UAs themselves generate
the From: header and that is what makes it the most unreliable and
unsecure source of caller-id.
To combat this problem, people came up with the Remote-Party-ID:
header and then the P-Asserted-ID: (RFC 3323) header. These headers
allowed a domain's authoritative proxy to insert the user's correct
identity in the message. But, these were deemed not secure and that's
when SIP-Identity (RFC 4474) came about, which allows a SIP proxy to
insert a user's cryptographic identity in a message and also sign it.
If the "last-mile" SIP provider were to render such a caller-id to the
UAS, there is *work involved* in decrypting the caller's identity and
authenticating the source that signed it.
--
Raj Jain |
|
| Back to top |
|
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Search
