1)I have configured many E1 implementations so far. But today while preparing for my CCNP i got this confusion. We use an E1 card for connecting a PRI. But i read E1 and PRI or different!
2)DS0 means Cas, Pri means CCS signalling, then for T1, E1 what we would use?
3)In a T1 we get total 24 channels, if we use CAS then we get 24 channels, and with CCS we get 23 channels. But for E1, when we use CCS we get only 30 B Channels and 1D channel, where as the 32nd Channel?
Kindly consider this as my learning and help me!
Solved! Go to Solution.
To clarify things:
ISDN runs on top of the T1/E1 circuits. There are two types of signaling:
- CCS : Common channel signaling (it uses a dedicated DS0 channel for the signaling)
- CAS : Channel Associated Signaling (it uses the data channel for signaling)
Now, PRI is an interface standard used on ISDN in order to carry multiple DS0 channels.
With this in mind:
- E1 PRI with CCS = 30 B channels and 1 D channel
- T1 PRI with CCS = 23 B channels and 1 D channel
- E1 PRI with CAS = 31 B Channels
- T1 PRI with CAS = 24 B Channels
This should also help you: VoIP with Common Channel Signaling (CCS)
So on a T1 PRI, you get 23 B channels for data/voice and one D channel for control.
If there are 46 PRI channels needed does that mean 2xT1 channelized ports are needed for the device?
Thanks in advance!