Re: SUA Address Indicator

Hi Chris,

Agreed and thanks, that is my understanding also. However I see no 
reason why bit 8 of the SUA Address Indicator is not encoded as per the 
SS7 SCCP's Address Indicator. At a minimum it would remove the 
requirement, as you pointed out, for the SG to have prior knowledge of 
the SCCP's NI.

regards,
Warren

Chris Benson wrote:

>Hi Warren,
>
>It is my understanding that bit 8 of the SS7 SCCP Address Indicator is 
>used to distinguish between a National and the International encodings of 
>the SS7 SCCP Address (including the rest of the Address Indicator bits) 
>and applies to the SS7 encoding only.
>
>For example, SSN and PC indicator positions are swapped between Telcordia 
>T1.112.3 Section 3.4.1 and ITU-T Q.713 Section 3.4.1 specifications. This 
>is indicated by bit 8 being 1 or 0 respectively.  SUA has no such 
>difference of encoding. Bit 8 of the SUA Address Indicator is spare 
>because there is only one SUA Address and Address Indicator format 
>specification (i.e. RFC 3868).
>
>This is easy for SCCP --> SUA. I think that the SUA --> SCCP direction 
>requires a priori knowledge of SCCP's National or International scope and  
>thus SS7 encoding format.
>
>This is only my understanding, and I would sure like to
>know if it is incorrect.
>
>With thanks, from Chris Benson.
>
>On Wed, 17 May 2006, Warren Anthony Briggs wrote:
>
>  
>
>>Hi All,
>>
>>Could you please clarify the following:
>>
>>Q.713. section 3.4.1   states that bit 8 of the SCCP Address Indicator 
>>parameter is reserved for national use.   RFC 3868 appears to indicate 
>>that this bit is spare and always 0.  Am I interpreting this correctly 
>>or should this bit have a 1 to 1 mapping  when encoding from SUA to SCCP 
>>and vice versa?
>>
>>thank you,
>>warren briggs.
>>
>>    
>>
>
>  
>