CCS / CAS in-band / out-of-band

Answered Question
Mar 20th, 2008
User Badges:

Found on wikipedia:

"Channel Associated Signaling (CAS), also known as Per-Trunk Signaling (PTS), is a form of digital communication signaling. As with most telecommunication signaling methods, it uses routing information to direct the payload of voice or data to its destination. With CAS signaling, this routing information is encoded and transmitted in the same channel as the payload itself. This information can be transmitted in the same band (in-band signaling) or a separate band (out-of-band signaling) to the payload."


I thought CAS was in-band signaling.

Do they mean with in-band and out-band the bands in the frequency spectrum?

Correct Answer by paolo bevilacqua about 9 years 1 month ago

Well, CAS with pulse dialing is actually out-of-band.

How it works, the A bit is toggled emulating the hook-switch in an analog telephone with rotary dial.

This is the only case that comes to mind, all the rest is in-band.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 3.5 (2 ratings)
Loading.
Jaime Valencia Thu, 03/20/2008 - 08:38
User Badges:
  • Cisco Employee,
  • Hall of Fame,

    2011

CAS means that if you have a T1 PRI you will get 24 voice calls, each DS0 contains within the same channel all the signaling for the call, that's in-band signaling


T1 PRI means you will get 23 calls, that's why it's referred ad 23B + 1D.

The D channel contains all the signaling for the other 23 channels, so it's not in the same DS0 as the voice, thus it's out of band


HTH


javalenc


if this helps, please rate

Correct Answer
paolo bevilacqua Thu, 03/20/2008 - 08:42
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

Well, CAS with pulse dialing is actually out-of-band.

How it works, the A bit is toggled emulating the hook-switch in an analog telephone with rotary dial.

This is the only case that comes to mind, all the rest is in-band.

woutereelen Thu, 03/20/2008 - 08:53
User Badges:

That's what I've been looking for.

I knew wikipedia wouldn't lie! :-)

Thanks p.bevilacqua.


Also thanks to the other person for answering my question, but I am familiar with CAS and CCS. I just didn't know any scenario where the signaling of CAS is send out-of-band.


br,

Wouter

Actions

This Discussion