Simplified solution for the TLDN conflict in the international call delivery

1
Simplified solution for the TLDN conflictin the
international call delivery

• IFAST-16
• Ixtapa, México
• May 15-16, 2001

2
Proposed solution to the TLDN conflict

• Activate TLDNs in the parameter digits to
  variable lenght up to 15 digits, as allowed in
  all the versions of IS-41.
• Additionally, to activate the international
  option in the field nature of the number of the
  parameter digits of IS-41D to determine if a
  TLDN is coming from a foreign country.

3
Simplified solution for networks without IS-41D

• Activate TLDNs in the parameter digits to
  variable lenght up to 15 digits, as allowed in
  all the versions of IS-41.
• Perform a prefix analysis to determine if the
  TLDN is international.

4
Practical implementation of the simplified
solution
Mexico MIN 52-5500-2186
GW GTE-TSI
4.- GTE-TSI adds the prefix 00 and the resulting
TLDN is of 12 digits routreq (00-384-448-7800)
3.- The Argentina switch returns a regular TLDN
of 10 digits routreq (384-448-7800)
2.- The Mexico switch sends a ROUTREQ
(52-5500-2186)
Switch Argentina
Switch Mexico
5.- The Mexico switch can receive the 12
digits. By prefix analysis, determines that is an
international number from Argentina, adds the
international prefix 54 and routes the number
00-54-384-448-7800 to the PSTN
6.- The PSTN delivers the call to the Argentina
switch
PSTN
1. A wireline Mexican user calls the Mexican
roamer
5
Simplified solution for 10 digits inthe national
number of Mexico
Mexico MIN 312-224-1234
STPs NACN
5.- The message routreq is not modified by
NACN routreq (011-52-55- 5101-5212)
4.- The Mexico switch returns a 15 digits
TLDN routreq (011-52-55- 5101-5212)
2.- The Chicago switch sends a ROUTREQ
(312-224-1234)
Switch Mexico
Switch Chicago
6.- The Chicago switch is able to receive 15
digits of the TLDN and only analyzing the prefix,
routes directly the call to the PSTN
3.- The switch is already prepared to send
more than 10 digits in the TLDN field
PSTN
1. A wireline user from Chicago calls the roamer
7.- The PSTN delivers the call to the Mexico
switch
6
Conclusion

• Many of the roaming partners have older versions
  of IS-41 and while they do not implement the
  newer revision D, the simplified solution can be
  implemented just to keep the international
  roaming with these partners.