SS7 Point Code

Like IP addresses in TCP/IP networks, point codes in SS7 networks identify individual network elments. Every element needs adress (a point code). Every link is considered point-to-point, but could be estabilshed from diffrent elements of SS7 Network, so it could be named from A-Link (B-Link..., C-Link) to F-Link. In most cases you either use A-Link or F-Link.

Identification of international SS7 SP's(Signalling Points) is done using a
Network Indicator NI=00 in the MTP(Message Transfer Part). Instead of our
24bit point code system, ISPCs (International Signalling Point Codes) are
only 14bit.

ISPC Format:
_
| N M L | K J I H G F E D | C B A |
| 3bits | 8bits | |
|<----------------------------------->|<--------->|
| Signalling Area Network Code (SANC) | SP ID* |
|<----------------------------------->|<--------->|
| International Signalling Point Code (ISPC) |
|<----------------------------------------------->|


  • SP ID= Signalling Point Identification

The first three most significant bits (NML) have a range of 0 to 7
The following eight bits (K-D) have a range of 000 to 255
The fields(bits) NML and K-D represent the SANC.

The three least significant bits (CBA) with a range of 0 to 7 identifies
an SP when combined with the SANC. This is an ISPC. (ex, 3-133-7)


An IP address is a four byte (each has 8 bits) integer (so 32 bit in total), noted for convinence like that:

3-133-7

or in decimal

7 + 133*8 + 3 * 4096 = 12288 (dec)

or hex:

3000 (hex)

in * you could use either the ISPC format ( so A-B-C) or decimal ( N ).


Telcordia Technologies is responsible for the administration and assignment of SS7 point codes in the United States and other North American Numbering Plan NANP countries.

See Also



Like IP addresses in TCP/IP networks, point codes in SS7 networks identify individual network elments. Every element needs adress (a point code). Every link is considered point-to-point, but could be estabilshed from diffrent elements of SS7 Network, so it could be named from A-Link (B-Link..., C-Link) to F-Link. In most cases you either use A-Link or F-Link.

Identification of international SS7 SP's(Signalling Points) is done using a
Network Indicator NI=00 in the MTP(Message Transfer Part). Instead of our
24bit point code system, ISPCs (International Signalling Point Codes) are
only 14bit.

ISPC Format:
_
| N M L | K J I H G F E D | C B A |
| 3bits | 8bits | |
|<----------------------------------->|<--------->|
| Signalling Area Network Code (SANC) | SP ID* |
|<----------------------------------->|<--------->|
| International Signalling Point Code (ISPC) |
|<----------------------------------------------->|


  • SP ID= Signalling Point Identification

The first three most significant bits (NML) have a range of 0 to 7
The following eight bits (K-D) have a range of 000 to 255
The fields(bits) NML and K-D represent the SANC.

The three least significant bits (CBA) with a range of 0 to 7 identifies
an SP when combined with the SANC. This is an ISPC. (ex, 3-133-7)


An IP address is a four byte (each has 8 bits) integer (so 32 bit in total), noted for convinence like that:

3-133-7

or in decimal

7 + 133*8 + 3 * 4096 = 12288 (dec)

or hex:

3000 (hex)

in * you could use either the ISPC format ( so A-B-C) or decimal ( N ).


Telcordia Technologies is responsible for the administration and assignment of SS7 point codes in the United States and other North American Numbering Plan NANP countries.

See Also



Created by: admin, Last modification: Sun 03 of Jan, 2010 (17:49 UTC) by krzys
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