Subject: [Megaco] interpretation of H.248.23 andisp package and the dwa/data signals

From: "Jan Lindquist \(AL/EAB\)" <[email-masked]>
Date: Mon, 25 Apr 2005 20:09:29 +0200

Hello megaco community,
 
This e-mail is a question to the megaco community and their
interpretation of the andisp package and the dwa and data signals.
 
Question 1:
 
The description of the display with alerting signal in H.248.23 has the
following text:
 
"Sends the display information to the CPE. This signal indicates that
the data must be applied during alerting - either power ringing, or call
waiting. Therefore, this signal implies alerting, which will be
appropriately applied to the CPE by the gateway, based upon the on
hook/off-hook status of the line."

The ETSI specification, EN 300 659-1, On-Hook Data Transmission, defines
the following data transmission methods:

1. prior to ringing (including TAS equal to Ringing Pulse-Alert Singal),

2. during ringing (ie between the first and second ringing pattern) 

Which signals defined in the andisp package should be used to support
the two methods because it is not clear from the andisp package
descrition for dwa signal can be applied for method 1?

Question 2:

Additionally it would be useful to find out what MG and MGC vendors have
implemented for methods 1 and 2.

Best Regards,
Jan Lindquist
_______________________________________________
Megaco mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/megaco

---

From: [email-masked]
Date: Tue, 26 Apr 2005 10:45:41 +0200

Hello Jan,

In fact  ETSI defines 7 different options for data transmission when the
subscriber is in on-hook state, and one additional procedure when the
subscriber is already in off-hook state.

Methods defined by ETSI are:
EN 300 659-1
      6.1.1- Data tx during ringing (between the first and second ringing
pulses)
      6.1.2- Data tx prior to ringing
            a)- Alerting signal = dual tone (DT-AS)
            b)- Alerting signal = short ringing pulse (RP-AS)
            c)- Alerting signal = line reversal + dual tone (LR+DT-AS)
      6.2- Data tx not associated with ringing
            a)- Alerting signal = dual tone (DT-AS)
            b)- Alerting signal = ringing pulse (RP-AS)
            c)- Alerting signal = line reversal + dual tone (LR+DT-AS)
EN 300 659-2
      6.1 Off-hook data transmission

In our experience all operators choose one generic method for delivering:
      I) - CID data for incoming calls: Either 6.1.1,  6.1.2.a, 6.1.2b or
6.1.2.c
      II) - CID data associated to the Call Waiting service:  6.1
      III)- Generic data not associated with alerting: Message Waiting
Indicator, Fixed SMS, etc: Either 6.2a, 6.2b or 6.2c.

All our gateways in Alcatel provide support for the 8 ETSI methods listed
above, plus some others specified by Telcordia or DTMF-based (out of
scope).

For each Gateway there is always a  default method provisioned for services
I, II and III, and also an specific set of timer values associated to each
method.

Gateways support both 'dwa' and 'data' signals, and map these H.248 signals
into line signalling procedures based on:
      - the actual termination hook state, and
      - default procedures provisioned in the gateway.

Rules applied by Gateways are summarized here:

andisp/dwa{ddb="octect string"}
      On-hook: No alerting, raw data
      Off-hook: No alerting, raw data
andisp/dwa{ddb="octect string", pattern='n'}
      On-hook: Alerting with provisioned method for service I), followed by
ringing cadence 'n'
      Off-hook: Service II), method 6.1 with Subscriber Alerting Signal
(SAS)

andisp/data{db="octect string"}
      On-hook: Alerting with provisioned method for service III)
      Off-hook: Service II), method 6.1, no SAS
andisp/data{db="octect string",tas=dt}
      On-hook: Alerting with method 6.2a
      Off-hook: Service II), method 6.1, no SAS
andisp/data{db="octect string",tas=rp}
      On-hook: Alerting with method 6.2b
      Off-hook: Service II), method 6.1, no SAS
andisp/data{db="octect string",tas=lr}
      On-hook: Alerting with method 6.2c
      Off-hook: Service II), method 6.1, no SAS
andisp/data{db="octect string",tas=nt}
      On-hook: No alerting, raw data
      Off-hook: No alerting, raw data

Regarding your question #1, if an operator wants to implement both methods
in the same network (very uncommon) our proposal would be:

1.- Prior to ringing
Signal andisp/dwa{db="octect string",tas=rp}, followed by signal
alert/ri{pattern='n'}

2.- During ringing
Default method provisioned in the Gateway for service I) = 6.1.1.
Signal = andisp/dwa{ddb="octect string", pattern='n'}.

A bit confusing, but I hope it helps anyhow.

Kind regards,
      Fernando Togores

                      "Jan Lindquist                                                                                                    
                      \(AL/EAB\)"               To:      <[email-masked]>                                                              
                      <jan.lindquist@er         cc:      [email-masked]                                                       
                      icsson.com>               Subject: [Megaco] interpretation of H.248.23 andisp package and the dwa/data            
                      Sent by:                  signals                                                                                 
                      megaco-bounces@ie                                                                                                 
                      tf.org                                                                                                            

                      25/04/05 20.09                                                                                                    

Hello megaco community,

This e-mail is a question to the megaco community and their interpretation
of the andisp package and the dwa and data signals.

Question 1:

"Sends the display information to the CPE. This signal indicates that the
data must be applied during alerting ? either power ringing, or call
waiting. Therefore, this signal implies alerting, which will be
appropriately applied to the CPE by the gateway, based upon the on
hook/off-hook status of the line."

Which signals defined in the andisp package should be used to support the
two methods because it is not clear from the andisp package descrition for
dwa signal can be applied for method 1?

Question 2:

Best Regards,
Jan Lindquist_______________________________________________
Megaco mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/megaco

---

From: "Wayne Cutler" <[email-masked]>
Date: Tue, 26 Apr 2005 10:10:27 +0100

Hi Fernando,

One query against your resonse :-

>Signal andisp/dwa{db="octect string",tas=rp}, followed by signal

The TAS parmeter does not exist in the dwa signal. Did you mean andisp/data
here ?

Reagrds
Wayne Cutler

---

From: [email-masked]
Date: Tue, 26 Apr 2005 11:12:44 +0200

Hi Wayne,

Thanks, you are right.  I meant signal andisp/data for option 1.

Regards,
      Fernando Togores

                      "Wayne Cutler"                                                                                                   
                      <Wayne.Cutler@ma         To:      Fernando TOGORES CABALLERO/ES/ALCATEL@ALCATEL                                  
                      rconi.com>               cc:      "Jan Lindquist \(AL/EAB\)" <[email-masked]>, [email-masked],      
                                               [email-masked]                                                                 
                      26/04/05 11.10           Subject: Re: [Megaco] interpretation of H.248.23 andisp package and the    dwa/data     
                                               signals                                                                                 

Hi Fernando,

Reagrds
Wayne Cutler

---

From: "Wayne Cutler" <[email-masked]>
Date: Tue, 26 Apr 2005 10:45:26 +0100

data must be applied during alerting ? either power ringing, or call
waiting. >Therefore, this signal implies alerting, which will be
appropriately applied to the CPE by the gateway, based upon the on
hook/off-hook status of the >line."

two methods because it is not clear from the andisp package descrition for
dwa >signal can be applied for method 1?

Hi Jan,

For question 1, we'd read h248.23 as meaning that andisp/dwa should be used
for option 2 (during ringing) and andisp/data for option 1 (prior to
ringing).

In terms of question 2, this is what the Marconi CA & MSAN has implemented.

Regards,
Wayne