This CDR has been brought to you from the letters B, F, and the symbol #

TWICE in the past month, I've bumped into CDRs from SS7 equipment in
Atlanta that include alphabetic characters and pound signs in the
calling party number (ANI) field of the CDR.

One of the calls was from 5176#0B600. (That's a phone number.)

What's going on here?

Advertisements

2 thoughts on “This CDR has been brought to you from the letters B, F, and the symbol #

  1. Mark- Did you ever get an answer to this question? I think I know what may be happening. Perhaps the number before the # is a VM pilot number? The D code would be consistent with the DTMF standard which includes a fourth column of A,B,C, and D keys — but not F. (These tones were used on Operator stations and old Autovon phones.) These tones are still used today in VM systems which are integrated using inband DTMF instead of SDMI. The tones would be transmitted immediately after the VM system answers to indicate what mailbox to put the call into. So, in this instance (5176#0B600) the 5176 number would likely be the VM system, and — in keeping with common practice, B would appear to indicate that a call was being forwarded on Busy from extension 600.

  2. Mark- Did you ever get an answer to this question? I think I know what may be happening. Perhaps the number before the # is a VM pilot number? The D code would be consistent with the DTMF standard which includes a fourth column of A,B,C, and D keys — but not F. (These tones were used on Operator stations and old Autovon phones.) These tones are still used today in VM systems which are integrated using inband DTMF instead of SDMI. The tones would be transmitted immediately after the VM system answers to indicate what mailbox to put the call into. So, in this instance (5176#0B600) the 5176 number would likely be the VM system, and — in keeping with common practice, B would appear to indicate that a call was being forwarded on Busy from extension 600.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s