[Asterisk-Users] Little confused about Caller ID

Tom Chandler tchandle at bayou.com
Sun Jan 9 19:43:28 MST 2005


These comments are based on domestic SS7.  International SS7 works different
and
when you internetwork between domestic and international SS7 everything
changes.
Sorry about long post......
TC.

----- Original Message -----
From: "C F" <shmaltz at gmail.com>
To: "Asterisk Users Mailing List - Non-Commercial Discussion"
<asterisk-users at lists.digium.com>
Sent: Sunday, January 09, 2005 7:14 PM
Subject: Re: [Asterisk-Users] Little confused about Caller ID


> Without going into detail of what the query is actualy called, when
> the called switch make the query to find out the name, does it ask it
> from the originating switch? or it askes it from the switch that is
> responsibble for servicing the number?

In the SS7 Data stream, the originating switch populates the IAM message in
which the
calling party number and some other flags are loaded.  The originating
switch can block
the terminating switch from doing a CNAME lookup.  This flag comes for the
Line Switch
Record in the originating switch.  But lets assume that it is not blocked.
The originating switch
populates the IAM message with the calling party name.  If the terminating
number has
callerid set, then the terminating switch will take the number from the SS7
record and do a
TCAP query for calling name.  So the originating switch will pass via the
SS7 IAM record
the calling party number.


> The difference would be if, I have a PRI from provider A, and a number
> from provider B, and thru provider A a make an outgoing call using the
> callerID of provider B, who recieves the query?

If your originating PBX or Switch does not have SS7 connection to up stream
switches, what will get loaded is the POTS number loaded with the PRI. This
assumes that it is Feature Group D.  If it is a 23B+D and your PBX can
support
it, over the D channel you can send a calling party number that can be
passed via
the next switch into the SS7 record if they will.  IT can be done, but may
not
based on tariffs, etc.

> In my experrience it doesn't matter, b/c most providers will anyhow
> ignore the name you send and just send the number (or is it the called
> switch that ignores it, and then makes the name query), and since I
> don't know how a query like this works I don't know why my provider
> doesn't answer with the name I supplied, if it is the one being asked,
> I beleive it will not generate names on the fly even if it the one
> being queried. But if the calling switch is the one being queried then
> it would at least in theory be possible to answer what ever I wanted.
> But if it askes the servicing switch (provider B) then it is not even
> possible to change it (at least thru A).

CNAME is designed to work on the terminating switch, the originating
switch via SS7 supplies the calling party number and what is referred to
as the FCI's.  (Forward calling indicators)

>
> I used to work with an Avaya Difinity G3. We had PRI, which gave us
> incoming CallerID (Name Only), and outgoing CallerID, since we had DID
> we set up the Difinity to send the DID as CallerID, we however also
> wanted that the name of the associated extension should come up, we
> were then told by our provider that the name will always be the
> billing name and there is nothing we can do. One day however a call
> came in from another company using a PRI, and a Difinity and the name
> of the remote extension came up, which leads me to believe that the
> name is sent along on PRI (remember on our PRI we never got incoming
> Name on CallerID). But it is ignored by the switches on the way, if
> the called end is analog the switch does the query (igonring the name
> that is sent, and sending the result of the query as the name), but if
> the called end is PRI it does not do a query (I guess it relies on
> your switch to do it), however it is sent along, on the PRI end your
> switch (in my case the Difinity) just has to read it, since our switch
> spoke the same language as the sending switch it received it and the
> name showed up on CallerID (we were both using a Difinity).
> Some clearfication please.

I retired from AT&T Labs.  Worked on these switches in a networking
config, using 23B + D.  The D channel can work as somewhat of a SS7
link.  Maybe that is what Asterisk should look at instead of SS7
connections.
To me Asterisk would work better if it could use the D channel for what
the D channel was designed for, instead of using system resources for SS7.
SS7 really works best in a TDM to TDM world.You can pass numbers out
of the PBX via the D channel to the upstream switch for inclusion in the IAM
message.
 Then next problem, is your upstream switch going to load these
names/numbers in
 the CNAME database.
If not then you will not get anything on the far end.  CNAME is a revenue
generator
for teleco.  Other telecos must pay a dip charge for looking up remote
names.

I have been looking at Asterisk and how to do local CNAME lookups based on
far end calls.  I can lookup based on NPA/NXX and get City State out of
MySQL.
Working on adding international.

Hope post was not too long, but will be glad to try and answer any other
questions.
Tom C.
> Thanks.
>
>
> On Sun, 9 Jan 2005 18:40:33 -0600, Tom Chandler <tchandle at bayou.com>
wrote:
> >
> > ----- Original Message -----
> > From: "Alexander Lopez" <alex.lopez at opsys.com>
> > To: "Asterisk Users Mailing List - Non-Commercial Discussion"
> > <asterisk-users at lists.digium.com>
> > Sent: Sunday, January 09, 2005 5:55 PM
> > Subject: RE: [Asterisk-Users] Little confused about Caller ID
> >
> > > Thanks. I was always under the impression that they were all separate
> > > tables in the same DB and that they were collectively called 'The
> > > LIDB!!'
> > >
> > > For my and the others here could you describe the function of the
> > > different DBs?
> > >
> > > I now understand the CNAME, I thought I knew the LIBD, I can guess on
> > > the LNP, and 800, but what about the AIN???
> > >
> >
> > AIN = Advanced Intellignet Network.  This is the area were a large
number of
> > new
> > applications in the SS7 world are going.    Followme calling, and some
> > others.
> > Some of the auto callback features, speed dial, etc.  These application
are
> > stored
> > in a database, and again require a TCAP query to make them work.
> >
> > There are other databases assoicated with Cellular that are completely
> > different from the
> > TDM world.
> >
> > > BTW. I was under the impression the fields had been added to the LIDB
to
> > > handle the Do Not Call list. Can anyone confirm or deny??
> >
> > I have not seen any documentation on this.  I think a large number of
people
> > get
> > LIDB and the Line Record Set which is in the switch interchanged.  The
Line
> > Record Set
> > is the record in the switch which configures the 7 digit line.  There
are
> > many flags in this record.
> > You can block Caller ID, Caller Name, auto callback, block out going LD,
> > etc.  The LIBD record
> > is in an SCP. The LIBD record and the Line Switch record are two
different
> > items.
> >
> > >
> > > -----Original Message-----
> > > From: asterisk-users-bounces at lists.digium.com
> > > [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Tom
> > > Chandler
> > > Sent: Sunday, January 09, 2005 6:54 PM
> > > To: Asterisk Users Mailing List - Non-Commercial Discussion
> > > Subject: Re: [Asterisk-Users] Little confused about Caller ID
> > >
> > > TCAP is a transaction application.  The CNAME, LIDB,800,.LNP and AIN
> > > database COULD
> > > be in the same SCP, but in most cases it is not.  LIDB database are
used
> > > for
> > > calling card, operator
> > > services, etc.  These are all seperate databases stored for use in an
> > > SCP
> > > connected to STP's.
> > > So is there a relationship between CNAME and LIBD, no.
> > > Tom C.
> > >
> > > ----- Original Message -----
> > > From: "Alexander Lopez" <alex.lopez at opsys.com>
> > > To: "Asterisk Users Mailing List - Non-Commercial Discussion"
> > > <asterisk-users at lists.digium.com>
> > > Sent: Sunday, January 09, 2005 5:44 PM
> > > Subject: RE: [Asterisk-Users] Little confused about Caller ID
> > >
> > >
> > > > Is the TCAP DB part of the LIDB collective (no Borg pun intended)??
> > > >
> > > > -----Original Message-----
> > > > From: asterisk-users-bounces at lists.digium.com
> > > > [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Tom
> > > > Chandler
> > > > Sent: Sunday, January 09, 2005 6:45 PM
> > > > To: Asterisk Users Mailing List - Non-Commercial Discussion; C F
> > > > Subject: Re: [Asterisk-Users] Little confused about Caller ID
> > > >
> > > > Caller Name is stored in a SCP.  It is a TCAP transaction.  The
> > > > receiving
> > > > switch via SS7 recieves
> > > > the calling party number in the ISUP message of the SS7 datastream.
> > > It
> > > > is
> > > > normally in the IAM mesasge.  Then a TCAP CNAME query is launched
from
> > > > the
> > > > called switch thru
> > > > the STP's to a SCP which has the calling name database.  The TCAP
> > > query
> > > > returns back to the launching
> > > > switch the caller name.  LIDB is for operator services etc. CNAME is
a
> > > > TCAP
> > > > database lookup, much
> > > > like 800 number translations.
> > > >
> > > > Tom C.
> > > >
> > > > ----- Original Message -----
> > > > From: "Alexander Lopez" <alex.lopez at opsys.com>
> > > > To: "C F" <shmaltz at gmail.com>; "Asterisk Users Mailing List -
> > > > Non-Commercial
> > > > Discussion" <asterisk-users at lists.digium.com>
> > > > Sent: Sunday, January 09, 2005 5:30 PM
> > > > Subject: RE: [Asterisk-Users] Little confused about Caller ID
> > > >
> > > >
> > > > > OK here it goes..
> > > > >
> > > > > Caller ID is two parts or actually three:
> > > > >
> > > > > Part 1 Number only
> > > > > Part 2 Number + Name
> > > > > Part 3 Whole lotta stuff (also known as ADSI)
> > > > >
> > > > >
> > > > > Here is the US, I cannot speak for other countries.
> > > > >
> > > > > When party A places a call to Party B. Party A's Telco picks up
the
> > > > > number, either from a table on the switch or passed from the PRI
> > > from
> > > > > Party A.  Then on the far side (Party B's Telco) the Telco does a
> > > > lookup
> > > > > in the LIDB (Line Information Data Base) and associates a name
with
> > > a
> > > > > number. This information is then passed as Part II CLID.
> > > > >
> > > > > I have simplified the process, leaving out many processes along
the
> > > > way
> > > > > but it should give some insight as to how the Name actually shows
up
> > > > on
> > > > > the other end.
> > > > >
> > > > > Most Telcos do not receive the Name as part of the data in the
call
> > > > > through the tandems b/w Telcos, they opt rather to do the lookup
in
> > > > the
> > > > > LIDB themselves.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > -----Original Message-----
> > > > > From: asterisk-users-bounces at lists.digium.com
> > > > > [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of C F
> > > > > Sent: Sunday, January 09, 2005 6:16 PM
> > > > > To: Asterisk Users Mailing List - Non-Commercial Discussion
> > > > > Subject: Re: [Asterisk-Users] Little confused about Caller ID
> > > > >
> > > > > When calling to the PSTN (outside VOIP or *) then you will not be
> > > able
> > > > > to supply the name of callerID even if you have a PRI. The only
> > > thing
> > > > > you can provide is the number and the receiving switch of the call
> > > is
> > > > > the one responsibble for attaching a name to the phone number thru
> > > > > SS7. If you have a SS7 switch then you could in theory attach the
> > > name
> > > > > (I have never tried it, but that's what I was told).
> > > > > Hope this helps.
> > > > >
> > > > >
> > > > >




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