Subject: [Tsvwg] RE: [Sigtran] DUA : Query about format of DLC status parameter

From: [email-masked]
Date: Wed, 19 Jul 2006 20:04:49 +0530

Hi Mike,

Thanks for  your inputs,

I have one more question 

If any establish/release/data message is received by DUA stack, for a NA 
(Not Applicable) channel (For ex : DLC D0 in case of DPNSS E1 interface)
what should the DUA stack implementation do?

whether DUA stack should return an error message or
It should provide the received message to L3 layer and it should be upto 
L3 layer to use this or not ?

Regards
Ankur Arora

"Michael Mentz" <[email-masked]> 
07/19/2006 06:22 PM

To
sigtran_maillist@HSS
cc
<[email-masked]>, <[email-masked]>, 
<[email-masked]>, <[email-masked]>, <[email-masked]>
Subject
RE: [Sigtran] DUA : Query about format of DLC status parameter

It is a matter of interpretation.
 
I was merely pointing out that DLC16 can send and receive  DASS2 Layer 2 
frames (SABMR/UA/UI(c)/UI(r)) in BTNR190/DASS2 but cannot in  DPNSS.
 
Therefore, DLC16 will have a layer 2 status (RA/RC/IT)  which must be 
reflected in the status message used to convery DLC status and  hence can 
be established and released from ASP as well.
BTNR190 only mentions it's use for any maintenance  decisions, so, DLC16 
cannot be used for voice. (DASS2 still has 30 traffic  channels only so 
RFC is fine).
 
Ultimately, it  would be up to the Layer 3 process to not use DLC16 for 
calls (and Layer 3 is  not a part of DUA). 
Since DUA is  providing an interface to control L2 only, it needs to be 
able to cope with  DLC16 having a status, and the RFC should reflect this 
as per my previous  mail.
 
Cheers,
Mike

From: Ankur Arora [mailto:[email-masked]]  On Behalf 
Of [email-masked]
Sent: 19  July 2006 13:06
To: Mentz, Michael (MOP:MA02)
Cc:  [email-masked]; [email-masked]; 
[email-masked];  [email-masked]; sigtran_maillist; 
[email-masked]
Subject: RE:  [Sigtran] DUA : Query about format of DLC status parameter

Hi Michael, 

As Per DUA RFC 
"Data Link  Connection(DLC) - A DLC is the level 2 process that
  controls the  transfer of level 3 messages on behalf of one DPNSS
  channel.  A  DLC uniquely identifies one DPNSS channel.

     -   DPNSS supports 60 DLCs (30 Real and 30 Virtual)
     -   DASSII supports 30 DLCs (All Real)" 

where DPNSS Channel is defined in RFC as 

"DPNSS channel - Time slots 1 to 15 and 17 to 31 on a 2048  kbits/s
  interface or Time slots 1 to 23 on a 1544 kbits/s interface  are
  termed as DPNSS channels.  These are the traffic channels  that carry
  voice or data traffic.

     -   DPNSS supports 60 Channels (30 Real and 30 Virtual)
      -  DASS2 supports 30 Channels (All Real)"

It means that a DLC uniquely identifies one DPNSS channel and the  DPNSS 
Channels 
are the traffic channels that  carry Voice or data traffic. 

Also section  1.1 in BTNR190 mentions 

" The transmission  system provides 30 * 64 Kbits/s traffic channels, 1 * 
64 Kbits/s 
frame alignment channel (time-slot 0) and 1 * 64 Kbit/s  channel for 
common channel 
signalling  (time-slot 16)." 

Hence, I think the format  for DASS2 (E1 interface)is correct in RFC. 
please 
comment on this. 

For tsvwg :- Please take this change in DUA RFC 

the Figure for T1 interface in section 2.4 

        0                    1                     2                     3 

  0 1 2 3 4 5 6 7 8  9 0 1 2 3 4 5  6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1   
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |            Tag (0x12)           |               Length              | 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 | D0| D1| D2| D3| D4| D5| D6| D7| D8|   D9|D10|D11|D12|D13|D14|D15| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |D16|D17|D18|D19|D20|D21|D22|   NA|D24|D25|D26|D27|D28|D29|D30|D31| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |  D32|D33|D34|D35|D36|D37|D38|D39|D40|D41|D42|D43|D44|D45|D46|  NA| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 

The DLC D32 is valid for DPNSS T1  interface. 

Regards 
Ankur Arora 

"Michael Mentz"  <[email-masked]>  

07/19/2006 03:54 PM 

To
sigtran_maillist@HSS 
cc
<[email-masked]>, <[email-masked]>, 
<[email-masked]>, <[email-masked]>,  <[email-masked]> 
Subject
RE: [Sigtran] DUA :  Query about format of DLC status parameter

Yes, there is a subtle statement in BTNR190, and I have  also seen  some 
DASS2 PBX's and converters send SABMR for  DLC16. 
They send null UI(c) frames on DLC16 as a generic means of   testing 
connectivity (by gaining a UI(r) back or not). 

From: Ankur Arora   [mailto:[email-masked]] On Behalf 
Of   [email-masked] 
Sent: 19 July 2006  11:25 
To:  Mentz, Michael (MOP:MA02) 
Cc:   [email-masked]; [email-masked]; 
[email-masked];  [email-masked]; [email-masked] 
Subject: RE: [Sigtran] DUA : Query  about format of  DLC status parameter 

Hi Michael, 

As mentioned by you 

 2.4.2 E1 ?   DASS2 
  
    0                     1                     2                    3   
    0 1 2 3 4 5 6  7 8 9  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   |            Tag (0x12)           |            Length (0xC)         |   

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   | NA| D1| D2| D3|  D4|  D5| D6| D7| D8| D9|D10|D11|D12|D13|D14|D15| 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
     |D16|D17|D18|D19|D20|D21|D22|D23|D24|D25|D26|D27|D28|D29|D30|D31|   
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
  
    NA stands for Not Applicable.  D0 is not applicable  because  timeslot 

  0 is used for E1 framing and  synchronization  bits. 
    DLC 16  is valid for DASS2 (BTNR190) but DASS2 does not have virtuals. 

My Views :- 

As per RFC, in case of DASS2 (E1 interface), there  would  be a total of 
30 DLCs (no virtuals). 
but  as per your format there is 31 DLCs (only D0  invalid). 

Are you sure about including D16 also.    

Regards 
Ankur Arora 

"Michael Mentz"   <[email-masked]>   

07/19/2006 02:32 PM 

To
Ankur Arora/HSS@HSS,   <[email-masked]>, <[email-masked]>, 
 <[email-masked]>    
cc

Subject
RE: [Sigtran] DUA :  Query about format of DLC  status parameter

Hi Ankur, 
  
I agree, T1 DASS2 would have the length set to 10   bytes accordingly, the 
rest filled up with padding 0's to nearest 4 bytes  as per  usual xUA 
message rules. 
  
worth noting that in the case of E1 (and  T1 I  think) DASS2, DLC 16 can 
be established (in DPNSS it cannot), so the  section  would look something 
like.. 
  
For your T1 DPNSS query, DLC32 would be   valid. 

2.4.1 E1 - DPNSS 
     etc.. etc.. Length   (0x14) 
  
2.4.2 E1 ? DASS2 
     
    0                     1                     2                     3 
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9  0  1 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   |            Tag (0x12)           |            Length (0xC)         |   

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   | NA| D1| D2| D3|  D4|  D5| D6| D7| D8| D9|D10|D11|D12|D13|D14|D15| 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
     |D16|D17|D18|D19|D20|D21|D22|D23|D24|D25|D26|D27|D28|D29|D30|D31|   
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
  
    NA stands for Not Applicable.  D0 is not applicable  because  timeslot 

  0 is used for E1 framing and  synchronization  bits. 
    DLC 16  is valid for DASS2 (BTNR190) but DASS2 does not have virtuals. 

2.4.3 T1 -  DPNSS 
  
    0                     1                     2                    3   
     0 1 2 3 4 5 6 7 8 9  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0  1 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   |            Tag (0x12)           |           Length (0x10)         |   

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   | D0| D1| D2| D3|  D4|  D5| D6| D7| D8| D9|D10|D11|D12|D13|D14|D15| 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
     |D16|D17|D18|D19|D20|D21|D22|  NA|D24|D25|D26|D27|D28|D29|D30|D31|   
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
     |D32|D33|D34|D35|D36|D37|D38|D39|D40|D41|D42|D43|D44|D45|D46|  NA|   
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
  
   D23 is not applicable for a T1   interface because timeslot 23 is used 
   for signalling.  For DPNSS, there would be a   total of max 46 DLCs 
   (23 real + 23  virtual) and in case of DASS2 there would be a  total 
   of 23  DLCs (no virtuals). 
  
2.4.4 T1 - DASS2 
  
     0                    1                     2                     3 
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0  1 2 3  4 5 6 7 8 9 0 1 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   |            Tag (0x12)           |            Length (0xA)         |   

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   |D0 | D1| D2| D3|  D4|  D5| D6| D7| D8| D9|D10|D11|D12|D13|D14|D15| 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
     |D16|D17|D18|D19|D20|D21|D22|NA | Padding Bytes                   | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
   NA stands  for  Not Applicable.  D23 is not applicable because timeslot 
 
  23 is  used for signalling. 
  
   DLC  16 is valid for DASS2  (BTNR190) but DASS2 does not have virtuals. 
 
  Padding bytes should be  set to all 0's and ignored  by the receiver. 

Hope this helps and makes it to the RFC.. 
Thanks, 
Mike 

From: Ankur Arora   [mailto:[email-masked]] 
Sent: 19 July 2006  06:07 
To:  [email-masked]; [email-masked]; Mentz, Michael  (MOP:MA02); 
 [email-masked] 
Subject: Fw:  [Sigtran]  DUA : Query about format of DLC status parameter 

Pls Comment 

----- Forwarded   by Ankur Arora/HSS on 07/19/2006 10:31 AM -----    
sigtran_maillist@HSS    

07/18/2006 06:59  PM   

To
ietf   <[email-masked]>   
cc

Subject
[Sigtran] DUA : Query  about format of DLC  status parameter

Hi,   

Query 1:-      

Please Confirm  whether the DLC status parameter for  DASS protocol has 
the following  format or not.   

For  DASS :-     
        E1 Interface :-   

       0                     1                     2                     3 
 
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2  3 4 5 6 7 8  9 0 1 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |            Tag (0x12)           |               Length              | 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 | NA| D1| D2| D3| D4| D5| D6| D7| D8|   D9|D10|D11|D12|D13|D14|D15| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |   NA|D17|D18|D19|D20|D21|D22|D23|D24|D25|D26|D27|D28|D29|D30|D31| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
  
       where length is 12 Bytes. 

For DASS :-   
       T1 Interface :-    

        0                    1                     2                     3 
  
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4  5 6 7 8 9 0 1 2  3 4 5 6 7 8 9 0 1 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |            Tag (0x12)           |               Length              | 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 | D0| D1| D2| D3| D4| D5| D6| D7| D8|   D9|D10|D11|D12|D13|D14|D15| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |D16|D17|D18|D19|D20|D21|D22| NA|                  Padding Bytes         
                   | 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      
       Where length  is 10  Bytes. 
         and 2 bytes are the Padding Bytes which should be set  to all 0's 
and  ignored by the receiver. 

Query 2  :- 

Section 2.4 DUA RFC    
For DPNSS (T1  Interface) :-   

"This parameter will have the following  format for a T1  interface: 

       0                     1                    2                      3 

  0 1 2 3 4 5  6 7 8  9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1   
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |            Tag (0x12)           |               Length              | 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 | D0| D1| D2| D3| D4| D5| D6| D7| D8|   D9|D10|D11|D12|D13|D14|D15| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |D16|D17|D18|D19|D20|D21|D22|   NA|D24|D25|D26|D27|D28|D29|D30|D31| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 |   NA|D33|D34|D35|D36|D37|D38|D39|D40|D41|D42|D43|D44|D45|D46|  NA| 
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      
  D23 is not applicable for a T1   interface because timeslot 23 is used 
 for signaling.  For DPNSS, there would be  a total of  max 46 DLCs (23 
 real  + 23 virtual)" 

So, as  per RFC there would be a total of  max 46 links for T1 interface, 
but    
the figure shows  that there are only 45 valid  links (where D23, D32 and 
D47   
are  Invalid/NA). According to my  understanding, one out  of two DLCs 
(D32 and D47)   
should be NA not both.   

Regards 
Ankur Arora 

***********************  FSS-Private     *********************** 
_______________________________________________ 
Sigtran  mailing  list 
[email-masked] 
https://www1.ietf.org/mailman/listinfo/sigtran 

***********************    FSS-Private   *********************** 

***********************  FSS-Private     *********************** 

***********************  FSS-Private    ***********************

***********************  FSS-Private   ***********************