Hi All There is a problem in the additions made to Q.931 part of Connect message in H.2250V3. Two new IEs have been added AFTER User-to-User IE. The IE codes for the new IEs added are: Connected Number : 0x4c Connected Subaddress: 0x4d The IE code for User-to-User is 0x7e According to Q.931 coding Rules [section: 4.5.1], the IEs in a message should be in ascending order of their respective code values. These two IEs should be added after Date/Time IE. Comments ? aseem@trillium.com
Aseem, This may be true for Q.931, but H.225.0 modifies the related tables found in Q.931. H.225.0 suggests in section 7.2.2 that the encoding shall follow rules in Q.931, but H.225.0 specifies the ordering. I see no problem with putting those fields at the end, especially considering that inserting new IEs in the middle may be more difficult to handle. It might be interesting to see what assumptions people have made. Do implementation expect an ordering? Would they expect new elements to be ordered numerically or at the end? Best Regards, Paul ----- Original Message ----- From: Aseem Agarwal <aseem@TRILLIUM.COM> To: <ITU-SG16@mailbag.cps.intel.com> Sent: Wednesday, November 17, 1999 5:43 PM Subject: Problem in Connect Message in H.2250 V3
Hi All
There is a problem in the additions made to Q.931 part of Connect message in H.2250V3. Two new IEs have been added AFTER User-to-User IE.
The IE codes for the new IEs added are: Connected Number : 0x4c Connected Subaddress: 0x4d
The IE code for User-to-User is 0x7e
According to Q.931 coding Rules [section: 4.5.1], the IEs in a message should be in ascending order of their respective code values. These two IEs should be added after Date/Time IE.
Comments ?
aseem@trillium.com
In looking at this again, I have to withdraw my previous comments below. H.225.0 specifies that the encoding of the elements shall follow Q.931. This would also imply the ordering, as H.225.0 does not specify a different ordering. I was mistaken in saying that H.225.0 specifies the ordering-- it does not. I will have to concur with Guntram Diehl, who posted a similar comment, that the tables in H.225.0 do not dictate an ordering of the information elements and that the ordering is dictated by Q.931. Now the question is "how important is it that the tables in H.225.0 show the elements in order"? Perhaps we should make this change to H.225.0v4. Aseem, do you feel that this warrants a change in the Implementers Guide? Paul ----- Original Message ----- From: Paul E. Jones <paul.jones@ties.itu.int> To: <ITU-SG16@mailbag.cps.intel.com> Sent: Wednesday, November 17, 1999 9:19 PM Subject: Re: Problem in Connect Message in H.2250 V3
Aseem,
This may be true for Q.931, but H.225.0 modifies the related tables found in Q.931. H.225.0 suggests in section 7.2.2 that the encoding shall follow rules in Q.931, but H.225.0 specifies the ordering.
I see no problem with putting those fields at the end, especially considering that inserting new IEs in the middle may be more difficult to handle.
It might be interesting to see what assumptions people have made. Do implementation expect an ordering? Would they expect new elements to be ordered numerically or at the end?
Best Regards, Paul
----- Original Message ----- From: Aseem Agarwal <aseem@TRILLIUM.COM> To: <ITU-SG16@mailbag.cps.intel.com> Sent: Wednesday, November 17, 1999 5:43 PM Subject: Problem in Connect Message in H.2250 V3
Hi All
There is a problem in the additions made to Q.931 part of Connect message in H.2250V3. Two new IEs have been added AFTER User-to-User IE.
The IE codes for the new IEs added are: Connected Number : 0x4c Connected Subaddress: 0x4d
The IE code for User-to-User is 0x7e
According to Q.931 coding Rules [section: 4.5.1], the IEs in a message should be in ascending order of their respective code values. These two IEs should be added after Date/Time IE.
Comments ?
aseem@trillium.com
Paul, As a practical matter, I have found that all entities with which we have tested place their IEs in order according to Q.931. I didn't know that our EPs expect them in this order until someone encoded them out of order at a recent interop, causing our EP to generate a diagnostic and drop the call. If my memory is correct, upon learning this, the vendor of the entity changed their code to place the IEs in order and we were then able to interop successfully. Paul Long Smith Micro Software, Inc. -----Original Message----- From: Paul E. Jones [mailto:paul.jones@TIES.ITU.INT] Sent: Saturday, November 20, 1999 12:21 AM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Problem in Connect Message in H.2250 V3 In looking at this again, I have to withdraw my previous comments below. H.225.0 specifies that the encoding of the elements shall follow Q.931. This would also imply the ordering, as H.225.0 does not specify a different ordering. I was mistaken in saying that H.225.0 specifies the ordering-- it does not. I will have to concur with Guntram Diehl, who posted a similar comment, that the tables in H.225.0 do not dictate an ordering of the information elements and that the ordering is dictated by Q.931. Now the question is "how important is it that the tables in H.225.0 show the elements in order"? Perhaps we should make this change to H.225.0v4. Aseem, do you feel that this warrants a change in the Implementers Guide? Paul
I feel that this definitely warrants a change in the next Implementor's Guide in order to avoid any ambiguity. aseem
In looking at this again, I have to withdraw my previous comments below.
H.225.0 specifies that the encoding of the elements shall follow Q.931. This would also imply the ordering, as H.225.0 does not specify a different ordering. I was mistaken in saying that H.225.0 specifies the ordering-- it does not.
I will have to concur with Guntram Diehl, who posted a similar comment, that the tables in H.225.0 do not dictate an ordering of the information elements and that the ordering is dictated by Q.931.
Now the question is "how important is it that the tables in H.225.0 show the elements in order"? Perhaps we should make this change to H.225.0v4. Aseem, do you feel that this warrants a change in the Implementers Guide?
Paul
----- Original Message ----- From: Paul E. Jones <paul.jones@ties.itu.int> To: <ITU-SG16@mailbag.cps.intel.com> Sent: Wednesday, November 17, 1999 9:19 PM Subject: Re: Problem in Connect Message in H.2250 V3
Aseem,
This may be true for Q.931, but H.225.0 modifies the related tables found in Q.931. H.225.0 suggests in section 7.2.2 that the encoding shall follow rules in Q.931, but H.225.0 specifies the ordering.
I see no problem with putting those fields at the end, especially considering that inserting new IEs in the middle may be more difficult to handle.
It might be interesting to see what assumptions people have made. Do implementation expect an ordering? Would they expect new elements to be ordered numerically or at the end?
Best Regards, Paul
----- Original Message ----- From: Aseem Agarwal <aseem@TRILLIUM.COM> To: <ITU-SG16@mailbag.cps.intel.com> Sent: Wednesday, November 17, 1999 5:43 PM Subject: Problem in Connect Message in H.2250 V3
Hi All
There is a problem in the additions made to Q.931 part of Connect message in H.2250V3. Two new IEs have been added AFTER User-to-User IE.
The IE codes for the new IEs added are: Connected Number : 0x4c Connected Subaddress: 0x4d
The IE code for User-to-User is 0x7e
According to Q.931 coding Rules [section: 4.5.1], the IEs in a message should be in ascending order of their respective code values. These two IEs should be added after Date/Time IE.
Comments ?
aseem@trillium.com
Paul and Aseem, To reduce ambiguity, rather than defining the order in H.225.0, let's clearly state in H.225.0 that the encoding order is defined in Q.931. The former would, IMO, lead to more confusion because an order would be defined in two places. Paul Long Smith Micro Software, Inc. -----Original Message----- From: Aseem Agarwal [mailto:aseem@TRILLIUM.COM] Sent: Monday, November 22, 1999 12:36 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Problem in Connect Message in H.2250 V3 I feel that this definitely warrants a change in the next Implementor's Guide in order to avoid any ambiguity. aseem
Paul, I agree. I'll add that to my growing list of issues to address at the next meeting. Paul ----- Original Message ----- From: Paul Long <plong@SMITHMICRO.COM> To: <ITU-SG16@mailbag.cps.intel.com> Sent: Monday, November 22, 1999 1:34 PM Subject: Re: Problem in Connect Message in H.2250 V3
Paul and Aseem,
To reduce ambiguity, rather than defining the order in H.225.0, let's clearly state in H.225.0 that the encoding order is defined in Q.931. The former would, IMO, lead to more confusion because an order would be defined in two places.
Paul Long Smith Micro Software, Inc.
-----Original Message----- From: Aseem Agarwal [mailto:aseem@TRILLIUM.COM] Sent: Monday, November 22, 1999 12:36 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Problem in Connect Message in H.2250 V3
I feel that this definitely warrants a change in the next Implementor's Guide in order to avoid any ambiguity.
aseem
participants (3)
-
Aseem Agarwal -
Paul E. Jones -
Paul Long