I've been using OpenSER 1.0.1 for the past couple of years, but I now need to add CNAM lookups. It looks like the presence module might be what I need, although from the looks if it, it's made to respond to lookups, instead of actually generate a query to another server for a lookup.
I'm looking at doing CNAM lookups with Verisign which look to interface with a SUBSCRIBE message, in which in return Verising sends back a NOTIFY message with one of the fields being "calling-name" which has the CNAM info in it.
Has anyone been succesful in implementing such a lookup with Verisign or another CNAM database provider?
Brian
Hi Brian!
If you need to trigger SUBSCRIBE you would need the pua module. You would need to write a new module which either sends SUBSCRIBE directly (via tm module) or which links into pua module (which support SUBSCRIBE/NOTIFY in a generic ways).
Do you have a specification of the CNAM lookup (Event: type, payload ...)
I am not used to CNAM (does not exist in Europe) - how does it work? Do you query the CNAM database during call setup - thus delaying the call setup until you got the answer from the lookup? Or is this an asynchronous mechanism?
regards klaus
Brian McCrary schrieb:
I've been using OpenSER 1.0.1 for the past couple of years, but I now need to add CNAM lookups. It looks like the presence module might be what I need, although from the looks if it, it's made to respond to lookups, instead of actually generate a query to another server for a lookup.
I'm looking at doing CNAM lookups with Verisign which look to interface with a SUBSCRIBE message, in which in return Verising sends back a NOTIFY message with one of the fields being "calling-name" which has the CNAM info in it.
Has anyone been succesful in implementing such a lookup with Verisign or another CNAM database provider?
Brian
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On Thu, Oct 23, 2008 at 07:02:38AM +0200, Klaus Darilion wrote:
Hello Klaus,
If you need to trigger SUBSCRIBE you would need the pua module. You would need to write a new module which either sends SUBSCRIBE directly (via tm module) or which links into pua module (which support SUBSCRIBE/NOTIFY in a generic ways).
Thanks for your response! I was not aware of the pua module. It looks like it would be a good starting point, especially with it's database functions. I think I need to get to work today in setting up a new test server so I can play with these new modules and see what changes need to be made.
Do you have a specification of the CNAM lookup (Event: type, payload ...)
I am not used to CNAM (does not exist in Europe) - how does it work? Do you query the CNAM database during call setup - thus delaying the call setup until you got the answer from the lookup? Or is this an asynchronous mechanism?
Yes, I will post the information I have from Verisign on how it works (a little lengthy but it does a good job of describing it). The idea is indeed to query the database during call setup, and wait for the answer. Then the lookup would be forwarded to the SIP phone, ideally in the From field or P-Asserted Identity giving the called party the name of who is calling them.
This info taken from the Verisign manual:
IP CNAM Connectivity -------------------- VeriSign's IP CNAM connectivity option provides IP access to calling name databases using the services of the Session Initiation Protocol (SIP). How IP CNAM Works CNAM Subscribers in the network can subscribe to CNAM Notifiers' name services on a per call basis. The CNAM Notifiers can broker those calling name subscriptions to either SS7-resident databases or IP-resident databases. The CNAM Notifiers, acting on behalf of the name databases, can send a notification when those calling name subscriptions are resolved into the name availability indicator, calling name, if present, and permanent privacy status associated with the calling directory number.
If the name is not to be delivered to the called end-user equipment because of a 'private' privacy status associated with the name, a 'From' header display-name parameter with a value of 'private' is sent to the called end-user equipment. If the name availability indicator reveals that the name is not available for delivery, a 'From' header display-name parameter with a value of 'out-of-area/unavailable' is sent to the called end-user equipment. Otherwise, a 'From' header display-name parameter containing the derived calling name is sent to the called end-user equipment.
Node Behavior ------------- This section describes how the CNAM subscriber and CNAM Notifier functions.
CNAM Subscriber Behavior
To achieve carrier-grade availability and optimal transaction rates, the CNAM Notifier is optimized to support stateless fetch transactions. When the subscribe request is transmitted by a CNAM Subscriber to a CNAM Notifier, this requirement translates to the 'Expires' header having a value of zero (0) or, alternatively, a subscribe request with no 'Expires' header present, which implies the default value of zero (0) as defined by the 'calling-name-info' event package [2]. This use of subscribe polling reduces the complexity of the calling name event, limiting the duration of the subscription to a single calling name fetch and avoiding the necessity to support state related procedures such as unsubscribing and refreshing subscriptions.
The Request URI of a subscribe request contains enough information to route the request to the appropriate CNAM Notifier, as listed in the request routing procedures outlined in SIP. For example, a SIP URI populated with the fully qualified domain name (FQDN) of the VeriSign Calling Name Gateway: sip:cnam-gateway.verisign.com. CNAM Subscribers must populate exactly one 'Event' header in the Subscriber request, indicating they are subscribing to the calling-name event ('Event: calling-name').1 Optionally, the CNAM Subscriber may also include within the 'Event' header an 'id' parameter, which contains an opaque token that identifies the specific calling name subscription within a SIP peer-to-peer dialog (e.g. 'Event:calling-name; id=2'). The CNAM Notifier includes this token, if present, in the corresponding Notify request.
CNAM Notifier Behavior
The CNAM Notifier confirms the Subscribe request with a final response. A '200 OK' response indicates that the calling name subscription has been accepted and that the CNAM Subscriber is authorized to subscribe to the requested calling name information.
Non-200 class final responses indicate that no subscription has been created, and no subsequent NOTIFY response is sent. For example, if the responsible IP-resident or SS7-resident name database is not out-of-service because of temporary overload conditions, transmission availability, or maintenance activities. The CNAM Notifier returns a '503 Service Unavailable' final response, containing a 'Retry-After' header, which the CNAM Subscriber makes use of to throttle subsequent traffic to the affected CNAM Notifier.
Once accepted with a '200 OK' response, under no circumstance should a calling name subscription extend for any longer than the time necessary for automated processing, such as the time required to query or timeout waiting for a response from an SS7-resident calling name database.
Upon completion, regardless of the outcome, the CNAM Notifier sends a Notify request containing a 'Subscription-State' header with a value of terminated ('Subscription-State: terminated').
The CNAM Notifier must populate the 'Event' header within the Notify request to indicate a response to the calling name subscription ('Event: calling-name'). Additionally, if the 'Event' header 'id' parameter was received in the corresponding Subscribe request, the CNAM Notifier must echo that value back to the CNAM Subscriber (e.g., 'Event: calling-name; id=2').
If the subscription request fails due to a processing error (errors experienced querying SS7-resident name database), the CNAM Notifier immediately informs the CNAM Subscriber by returning a Notify request, which includes the 'calling-name-info' event package body indicating an 'out-of-service' availability. Otherwise the CNAM Notifier must construct and send a Notify request that includes the calling name information (name availability, display-name if available, and permanent privacy status).
Event Package ------------- Event Package Name
'calling-name' is the token designated as the event identifier for the calling-name-info event package. Event Packet Parameters This event package does not define any new 'Event' header parameters.
SUBSCRIBE Body
This mandatory section of the calling-name-info event package defines the event body expected in Subscriber requests. The Subscribe body contains the calling-name-request portion of the calling-name-info event package, indicating address-of-record of callee and optionally the called party. The calling-name-request syntax is as follows:
calling-name-request = callee CRLF [ called CRLF ] callee ="Calling-Party" HCOLON addr-spec called ="Called-Party" HCOLON addr-spec addr-spec =SIP URI / SIPS URI / TEL URI Example: Calling-Party: sip: 9726840623@cnam-subscriber;user=phone
NOTIFY Body
This mandatory section of the calling-name-info event package defines the event body expected in Notify requests. The Notify body contains the calling-name-response portion of the calling-name-info event, indicating the availability of the display-name, display-name if present, and the permanent privacy status. The syntax of the calling-name-response is as follows:
calling-name-response =calling-name-status CRLF [calling-name CRLF] [presentation-indicator CRLF] calling-name-status ="Calling-Name-Status" HCOLON calling-nameavailability calling-name-availability ="available" / "unavailable" / "out-of-service" calling-name ="Called-party" HCOLON name-addr name-addr =[ display-name ] LAQUOT addr-spec RAQUOT display-name =* (token LWS) / quoted-string addr-spec =SIP URI / SIPS URI / TEL URI presentation-indicator ="Presentation-Indicator" HCOLON "allowed / "restricted"/ "toggled" / "no indication"
Examples: Calling-Name-Status: available Calling-Name: "Joe Smith" sip:9726840623@cnam-subscriber.com;user=phone Presentation-Indicator: allowed
Message Flow Samples
In the following example, the 200 OK final response messages are omitted for brevity.
A1: SUBSCRIBE Message
SUBSCRIBER sip:cnam-notifier.com SIP/2.0 Via: SIP/2.0/UDP cnam-subscriber.com;branch=z9hG4bKnashds8 To: sip:cnam-notifier.com From: sip:cnam-subscriber.com;tag=1234 Call-ID: a84b4c76e66710 CSeq: 314159 SUBSCRIBE Max-Forwards: 10 Contact: sip:cnam-subscriber.com Expires: 0 Event: calling-name; id=2 Content-Type: application/calling-name-info Content-Length: 54 Calling-Party:sip:9726840623@cnam-subscriber.com;user=phone
A2: NOTIFY Message
NOTIFY sip:cnam-subcriber.com SIP/2.0 Via: SIP/2.0/UDP cnam-notifier.com;branch=a1hB4bGnashds4 To: sip:cnam-subscriber.com;tag=1234 From: sip:cnam-notifier.com;tag=5678 Call-ID: a84b4c76e66710 CSeq: 951413 NOTIFY Max-Forwards: 10 Contact: sip:cnam-notifier.com Event: calling-name; id=2 Subscription-State: terminated Content-Type: application/calling-name-info Content-Length:130 Calling-Name-Status: available Calling-Party: "Joe Smith" sip:9726840623@cnam-subscriber.com;user=phone Presentation-Indicator: allowed
Brian
Brian McCrary schrieb:
On Thu, Oct 23, 2008 at 07:02:38AM +0200, Klaus Darilion wrote:
Hello Klaus,
If you need to trigger SUBSCRIBE you would need the pua module. You would need to write a new module which either sends SUBSCRIBE directly (via tm module) or which links into pua module (which support SUBSCRIBE/NOTIFY in a generic ways).
Thanks for your response! I was not aware of the pua module. It looks like it would be a good starting point, especially with it's database functions. I think I need to get to work today in setting up a new test server so I can play with these new modules and see what changes need to be made.
Do you have a specification of the CNAM lookup (Event: type, payload ...)
I am not used to CNAM (does not exist in Europe) - how does it work? Do you query the CNAM database during call setup - thus delaying the call setup until you got the answer from the lookup? Or is this an asynchronous mechanism?
Yes, I will post the information I have from Verisign on how it works (a little lengthy but it does a good job of describing it). The idea is indeed to query the database during call setup, and wait for the answer. Then the lookup would be forwarded to the SIP phone, ideally in the From field or P-Asserted Identity giving the called party the name of who is calling them.
If the INVITE needs to get blocked during the lookup (to wait for the name) I wonder why the lookup is done asynchronous. IMO a simple HTTP request would be more efficient.
Of course if the INVITE is forward immediately and once the lookup finished an UPDATE with the CNAME is sent, then this sounds useful. But generating UPDATEs would require a B2BUA.
In general I think this is not easy to achieve with Kamailio as you have to delay the INVITE till the NOTIFY is received. Due to the Kamailio architecture this will easily block all Kamailio processes and thus Kamailio can not process the NOTIFYs anymore.
regards klaus
--SUBSCRIBEt-->
This info taken from the Verisign manual:
IP CNAM Connectivity
VeriSign's IP CNAM connectivity option provides IP access to calling name databases using the services of the Session Initiation Protocol (SIP). How IP CNAM Works CNAM Subscribers in the network can subscribe to CNAM Notifiers' name services on a per call basis. The CNAM Notifiers can broker those calling name subscriptions to either SS7-resident databases or IP-resident databases. The CNAM Notifiers, acting on behalf of the name databases, can send a notification when those calling name subscriptions are resolved into the name availability indicator, calling name, if present, and permanent privacy status associated with the calling directory number.
If the name is not to be delivered to the called end-user equipment because of a 'private' privacy status associated with the name, a 'From' header display-name parameter with a value of 'private' is sent to the called end-user equipment. If the name availability indicator reveals that the name is not available for delivery, a 'From' header display-name parameter with a value of 'out-of-area/unavailable' is sent to the called end-user equipment. Otherwise, a 'From' header display-name parameter containing the derived calling name is sent to the called end-user equipment.
Node Behavior
This section describes how the CNAM subscriber and CNAM Notifier functions.
CNAM Subscriber Behavior
To achieve carrier-grade availability and optimal transaction rates, the CNAM Notifier is optimized to support stateless fetch transactions. When the subscribe request is transmitted by a CNAM Subscriber to a CNAM Notifier, this requirement translates to the 'Expires' header having a value of zero (0) or, alternatively, a subscribe request with no 'Expires' header present, which implies the default value of zero (0) as defined by the 'calling-name-info' event package [2]. This use of subscribe polling reduces the complexity of the calling name event, limiting the duration of the subscription to a single calling name fetch and avoiding the necessity to support state related procedures such as unsubscribing and refreshing subscriptions.
The Request URI of a subscribe request contains enough information to route the request to the appropriate CNAM Notifier, as listed in the request routing procedures outlined in SIP. For example, a SIP URI populated with the fully qualified domain name (FQDN) of the VeriSign Calling Name Gateway: sip:cnam-gateway.verisign.com. CNAM Subscribers must populate exactly one 'Event' header in the Subscriber request, indicating they are subscribing to the calling-name event ('Event: calling-name').1 Optionally, the CNAM Subscriber may also include within the 'Event' header an 'id' parameter, which contains an opaque token that identifies the specific calling name subscription within a SIP peer-to-peer dialog (e.g. 'Event:calling-name; id=2'). The CNAM Notifier includes this token, if present, in the corresponding Notify request.
CNAM Notifier Behavior
The CNAM Notifier confirms the Subscribe request with a final response. A '200 OK' response indicates that the calling name subscription has been accepted and that the CNAM Subscriber is authorized to subscribe to the requested calling name information.
Non-200 class final responses indicate that no subscription has been created, and no subsequent NOTIFY response is sent. For example, if the responsible IP-resident or SS7-resident name database is not out-of-service because of temporary overload conditions, transmission availability, or maintenance activities. The CNAM Notifier returns a '503 Service Unavailable' final response, containing a 'Retry-After' header, which the CNAM Subscriber makes use of to throttle subsequent traffic to the affected CNAM Notifier.
Once accepted with a '200 OK' response, under no circumstance should a calling name subscription extend for any longer than the time necessary for automated processing, such as the time required to query or timeout waiting for a response from an SS7-resident calling name database.
Upon completion, regardless of the outcome, the CNAM Notifier sends a Notify request containing a 'Subscription-State' header with a value of terminated ('Subscription-State: terminated').
The CNAM Notifier must populate the 'Event' header within the Notify request to indicate a response to the calling name subscription ('Event: calling-name'). Additionally, if the 'Event' header 'id' parameter was received in the corresponding Subscribe request, the CNAM Notifier must echo that value back to the CNAM Subscriber (e.g., 'Event: calling-name; id=2').
If the subscription request fails due to a processing error (errors experienced querying SS7-resident name database), the CNAM Notifier immediately informs the CNAM Subscriber by returning a Notify request, which includes the 'calling-name-info' event package body indicating an 'out-of-service' availability. Otherwise the CNAM Notifier must construct and send a Notify request that includes the calling name information (name availability, display-name if available, and permanent privacy status).
Event Package
Event Package Name
'calling-name' is the token designated as the event identifier for the calling-name-info event package. Event Packet Parameters This event package does not define any new 'Event' header parameters.
SUBSCRIBE Body
This mandatory section of the calling-name-info event package defines the event body expected in Subscriber requests. The Subscribe body contains the calling-name-request portion of the calling-name-info event package, indicating address-of-record of callee and optionally the called party. The calling-name-request syntax is as follows:
calling-name-request = callee CRLF [ called CRLF ] callee ="Calling-Party" HCOLON addr-spec called ="Called-Party" HCOLON addr-spec addr-spec =SIP URI / SIPS URI / TEL URI Example: Calling-Party: sip: 9726840623@cnam-subscriber;user=phone
NOTIFY Body
This mandatory section of the calling-name-info event package defines the event body expected in Notify requests. The Notify body contains the calling-name-response portion of the calling-name-info event, indicating the availability of the display-name, display-name if present, and the permanent privacy status. The syntax of the calling-name-response is as follows:
calling-name-response =calling-name-status CRLF [calling-name CRLF] [presentation-indicator CRLF] calling-name-status ="Calling-Name-Status" HCOLON calling-nameavailability calling-name-availability ="available" / "unavailable" / "out-of-service" calling-name ="Called-party" HCOLON name-addr name-addr =[ display-name ] LAQUOT addr-spec RAQUOT display-name =* (token LWS) / quoted-string addr-spec =SIP URI / SIPS URI / TEL URI presentation-indicator ="Presentation-Indicator" HCOLON "allowed / "restricted"/ "toggled" / "no indication"
Examples: Calling-Name-Status: available Calling-Name: "Joe Smith" sip:9726840623@cnam-subscriber.com;user=phone Presentation-Indicator: allowed
Message Flow Samples
In the following example, the 200 OK final response messages are omitted for brevity.
A1: SUBSCRIBE Message
SUBSCRIBER sip:cnam-notifier.com SIP/2.0 Via: SIP/2.0/UDP cnam-subscriber.com;branch=z9hG4bKnashds8 To: sip:cnam-notifier.com From: sip:cnam-subscriber.com;tag=1234 Call-ID: a84b4c76e66710 CSeq: 314159 SUBSCRIBE Max-Forwards: 10 Contact: sip:cnam-subscriber.com Expires: 0 Event: calling-name; id=2 Content-Type: application/calling-name-info Content-Length: 54 Calling-Party:sip:9726840623@cnam-subscriber.com;user=phone
A2: NOTIFY Message
NOTIFY sip:cnam-subcriber.com SIP/2.0 Via: SIP/2.0/UDP cnam-notifier.com;branch=a1hB4bGnashds4 To: sip:cnam-subscriber.com;tag=1234 From: sip:cnam-notifier.com;tag=5678 Call-ID: a84b4c76e66710 CSeq: 951413 NOTIFY Max-Forwards: 10 Contact: sip:cnam-notifier.com Event: calling-name; id=2 Subscription-State: terminated Content-Type: application/calling-name-info Content-Length:130 Calling-Name-Status: available Calling-Party: "Joe Smith" sip:9726840623@cnam-subscriber.com;user=phone Presentation-Indicator: allowed
Brian
Klaus Darilion klaus.mailinglists@pernau.at wrote:
I am not used to CNAM (does not exist in Europe) - how does it work? Do you query the CNAM database during call setup - thus delaying the call setup until you got the answer from the lookup? Or is this an asynchronous mechanism?
I'm familiar with another CNAM provider -- they sent us an SDK (a static library and header files), we wrote a module that does CNAM queries asynchronously during call setup.
Just sayin' ;-)
Sajith T S schrieb:
Klaus Darilion klaus.mailinglists@pernau.at wrote:
I am not used to CNAM (does not exist in Europe) - how does it work? Do you query the CNAM database during call setup - thus delaying the call setup until you got the answer from the lookup? Or is this an asynchronous mechanism?
I'm familiar with another CNAM provider -- they sent us an SDK (a static library and header files), we wrote a module that does CNAM queries asynchronously during call setup.
What do you mean with "asynchronously"? Do you forward the INVITE without waiting for the CNAM response?
regards klaus
Klaus Darilion klaus.mailinglists@pernau.at wrote:
What do you mean with "asynchronously"? Do you forward the INVITE without waiting for the CNAM response?
Yes, CNAM queries were in a different thread.
Sajith T S schrieb:
Klaus Darilion klaus.mailinglists@pernau.at wrote:
What do you mean with "asynchronously"? Do you forward the INVITE without waiting for the CNAM response?
Yes, CNAM queries were in a different thread.
So, how do you send the Name to the callee once the CNAM response is received?
regards klaus
Klaus Darilion klaus.mailinglists@pernau.at wrote:
So, how do you send the Name to the callee once the CNAM response is received?
By calling CNAM as early as possible in INVITE processing, and then hoping for the best. :) (And I guess it could be sent in the subsequent messages if at all possible, but I'm not sure. I was trying to recall the details myself because this is pretty old code we're talking about..)
Predictably enough, this did not work well all the time and so customers did complain our claims of supplying caller name are wrong. Of course it is hard to guarantee that CNAM will work all the time unless we are willing to delay or drop calls.
-
Brian McCrary -
Klaus Darilion -
Sajith T S