# CAS mode switching

This topic contains the following CAS mode switching information:

- CAS switching limitations

- CAS mode switch model

- H.110 and local streams

- Voice and signaling information routing on T1 trunks

- Voice and signaling information routing on E1 trunks

- Default connections

## CAS switching limitations

CG 6565C boards terminate CAS signaling on local T1 and E1 trunks. In CAS mode, CG 6565C boards support signaling streams on the DSPs and the framers. These streams are provided for backward compatibility with applications that switch signaling streams.

The CG 6565C switch model supports full duplex connections between DSP signaling and trunk signaling. However, no other CAS signaling connections are supported by the CG 6565C board.

CG 6565C boards do not support DSP-to-DSP signaling connections (such as local stream:timeslot 66:0 to local stream:timeslot 67:4), trunk-to-trunk signaling connections (such as local stream:timeslot 2:0 to local stream:timeslot 7:3), or signaling-to-bus connections (such as local stream:timeslot 2:0 to MVIP stream:timeslot 0:0 or local stream:timeslot 66:0 to MVIP stream:timeslot 0:0).

## CAS mode switch model

The following illustration shows the CG 6565C switching model in CAS
mode:

## H.110 and local streams

The following tables list the specific use of each stream
in the CG 6565C CAS switching model:

### H.110 streams

H.110 bus | Streams 0..31, timeslots 0..127 (Streams clocked at 8 MHz)

### Local streams

Trunk voice information (T1 trunks) | Trunk 1: Streams 0 and 1 Trunk 2: Streams 4 and 5 Trunk 3: Streams 8 and 9 Trunk 4: Streams 12 and 13 Trunk 5: Streams 16 and 17 Trunk 6: Streams 20 and 21 Trunk 7: Streams 24 and 25 Trunk 8: Streams 28 and 29 Trunk 9: Streams 32 and 33 Trunk 10: Streams 36 and 37 Trunk 11: Streams 40 and 41 Trunk 12: Streams 44 and 45 Trunk 13: Streams 48 and 49 Trunk 14: Streams 52 and 53 Trunk 15: Streams 56 and 57 Trunk 16: Streams 60 and 61 | timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23
Trunk voice information (E1 trunks) | Trunk 1: Streams 0 and 1 Trunk 2: Streams 4 and 5 Trunk 3: Streams 8 and 9 Trunk 4: Streams 12 and 13 Trunk 5: Streams 16 and 17 Trunk 6: Streams 20 and 21 Trunk 7: Streams 24 and 25 Trunk 8: Streams 28 and 29 Trunk 9: Streams 32 and 33 Trunk 10: Streams 36 and 37 Trunk 11: Streams 40 and 41 Trunk 12: Streams 44 and 45 Trunk 13: Streams 48 and 49 Trunk 14: Streams 52 and 53 Trunk 15: Streams 56 and 57 Trunk 16: Streams 60 and 61 | timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29
Trunk signaling information (T1 trunks) | Trunk 1: Streams 2 and 3 Trunk 2: Streams 6 and 7 Trunk 3: Streams 10 and 11 Trunk 4: Streams 14 and 15 Trunk 5: Streams 18 and 19 Trunk 6: Streams 22 and 23 Trunk 7: Streams 26 and 27 Trunk 8: Streams 30 and 31 Trunk 9: Streams 34 and 35 Trunk 10: Streams 38 and 39 Trunk 11: Streams 42 and 43 Trunk 12: Streams 46 and 47 Trunk 13: Streams 50 and 51 Trunk 14: Streams 54 and 55 Trunk 15: Streams 58 and 59 Trunk 16: Streams 62 and 63 | timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23 timeslots 0..23
Trunk signaling information (E1 trunks) | Trunk 1: Streams 2 and 3 Trunk 2: Streams 6 and 7 Trunk 3: Streams 10 and 11 Trunk 4: Streams 14 and 15 Trunk 5: Streams 18 and 19 Trunk 6: Streams 22 and 23 Trunk 7: Streams 26 and 27 Trunk 8: Streams 30 and 31 Trunk 9: Streams 34 and 35 Trunk 10: Streams 38 and 39 Trunk 11: Streams 42 and 43 Trunk 12: Streams 46 and 47 Trunk 13: Streams 50 and 51 Trunk 14: Streams 54 and 55 Trunk 15: Streams 58 and 59 Trunk 16: Streams 62 and 63 | timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29 timeslots 0..29
DSP voice information | Streams 64 and 65, timeslots 0.. up to 1500
DSP signaling information | Streams 66 and 67, timeslots 0..511

## Voice and signaling information routing on T1 trunks (CAS mode)

If NetworkInterface.T1E1[x].SignalingType = CAS (the default setting), voice and signaling information is routed to accommodate a T1 channel associated signaling configuration. Voice information is transmitted in each channel on the T1 trunk and each channel is placed in a corresponding timeslot
on the local bus.

Signaling information is transmitted in each channel using robbed-bit signaling. The signaling information is broken out and placed on the corresponding signaling stream for that trunk. The signaling information for a given channel is placed in the same timeslot number as the voice information for that channel.

Note: The CG 6565C board does not allow signaling streams to be connected to the CT bus.

The following illustration shows how data is assigned to timeslots on a T1 trunk (CAS mode):

## Voice and signaling information routing on E1 trunks (CAS mode)

Regardless of the NetworkInterface.T1E1[x].SignalingType setting, the CG 6565C board routes voice information by assigning E1 timeslots 1 through 15 to the local bus timeslots 0..14. E1 timeslots 17 through 31 are assigned to the local bus timeslots 15..29. Timeslot 0 on the E1 line carries framing data.

The following illustration shows how voice channel data is assigned to timeslots (CAS mode):

If NetworkInterface.T1E1[x].SignalingType = CAS (the default setting), signaling information is routed to accommodate channel associated signaling. Line channel 16 carries the signaling information for all channels.

Signaling information is broken out and placed on the corresponding signaling stream for that trunk. The signaling information for a given channel is placed in the same timeslot number as the voice information for that channel.

Note: The CG 6565C board does not allow signaling streams to be connected to the CT bus.

The following illustration shows how signaling data is distributed from E1 stream 16 (CAS mode). Although the streams are shown here, they cannot be switched to the CT bus:

## Default connections (CAS mode)

If a board is configured for standalone operation (Clocking.HBus.ClockMode = STANDALONE), the DSPs and trunks are connected as shown in the following tables.

Note: The SwitchConnections keyword can override this setting.

The exact settings for CG 6565C boards configured as T1 or E1 depend upon the setting of the NetworkInterface.T1E1[x].SignalingType keyword.

The Voice information and DSP resources table and the Signaling information and DSP resources table show the default routing for CG 6565C boards in CAS mode.

### Voice information and DSP resources

Trunk type | Full duplex connection between the trunk voice information and the DSP resources...
--- | ---
T1 | Trunk 1: 0:0..23 => 65:0..23 Trunk 2: 4:0..23 => 65:24..47 Trunk 3: 8:0..23 => 65:48..71 Trunk 4: 12:0..23 => 65:72..95 Trunk 5: 16:0..23 => 65:96..119 Trunk 6: 20:0..23 => 65:120..143 Trunk 7: 24:0..23 => 65:144..167 Trunk 8: 28:0..23 => 65:168..191 Trunk 9: 32:0..23 => 65:192..215 Trunk 10: 36:0..23 => 65:216..239 Trunk 11: 40:0..23 => 65:240..263 Trunk 12: 44:0..23 => 65:264..287 Trunk 13: 48:0..23 => 65:288..311 Trunk 14: 52:0..23 => 65:312..335 Trunk 15: 56:0..23 => 65:336..359 Trunk 16: 60:0..23 => 65:360..383 | 64:0..23 => 1:0..23 64:24..47 => 5:0..23 64:48..71 => 9:0..23 64:72..95 => 13:0..23 64:96..119 => 17:0..23 64:120..143 => 21:0..23 64:144..167 => 25:0..23 64:168..191 => 23:0..23 64:192..215 => 33:0..23 64:216..239 => 37:0..23 64:240..263 => 41:0..23 64:264..287 => 45:0..23 64:288..311 => 49:0..23 64:312..335 => 53:0..23 64:336..359 => 57:0..23 64:360..383 => 61:0..23
E1 | Trunk 1: 0:0..29 => 65:0..29 Trunk 2: 4:0..29 => 65:30..59 Trunk 3: 8:0..29 => 65:60..89 Trunk 4: 12:0..29 => 65:90..119 Trunk 5: 16:0..29 => 65:120..149 Trunk 6: 20:0..29 => 65:150..179 Trunk 7: 24:0..29 => 65:180..209 Trunk 8: 28:0..29 => 65:210..239 Trunk 9: 32:0..29 => 65:240..269 Trunk 10: 36:0..29 => 65:270..299 Trunk 11: 40:0..29 => 65:300..329 Trunk 12: 44:0..29 => 65:330..359 Trunk 13: 48:0..29 => 65:360..389 Trunk 14: 52:0..29 => 65:390..419 Trunk 15: 56:0..29 => 65:420..449 Trunk 16: 60:0..29 => 65:450..479 | 64:0..29 => 1:0..29 64:30..59 => 5:0..29 64:60..89 => 9:0..29 64:90..119 => 13:0..29 64:120..149 => 17:0..29 64:150..179 => 21:0..29 64:180..209 => 25:0..29 64:210..239 => 29:0..29 64:240..269 => 33:0..29 64:270..299 => 37:0..29 64:300..329 => 41:0..29 64:330..359 => 45:0..29 64:360..389 => 49:0..29 64:390..419 => 53:0..29 64:420..449 => 57:0..29 64:450..479 => 61:0..29

### Signaling information and DSP resources

Trunk type | Full duplex connection between trunk signaling information and the DSP resources...
--- | ---
T1 | Trunk 1: 2:0..23 => 67:0..23 Trunk 2: 6:0..23 => 67:24..47 Trunk 3: 10:0..23 => 67:48..71 Trunk 4: 14:0..23 => 67:72..95 Trunk 5: 18:0..23 => 67:96..119 Trunk 6: 22:0..23 => 67:120..143 Trunk 7: 26:0..23 => 67:144..167 Trunk 8: 30:0..23 => 67:168..191 Trunk 9: 34:0..23 => 67:192..215 Trunk 10: 38:0..23 => 67:216..239 Trunk 11: 42:0..23 => 67:240..263 Trunk 12: 46:0..23 => 67:264..287 Trunk 13: 50:0..23 => 67:288..311 Trunk 14: 54:0..23 => 67:312..335 Trunk 15: 58:0..23 => 67:336..359 Trunk 16: 62:0..23 => 67:360..383 | 66:0..23 => 3:0..23 66:24..47 => 7:0..23 66:48..71 => 11:0..23 66:72..95 => 15:0..23 66:96..119 => 19:0..23 66:120..143 => 23:0..23 66:144..167 => 27:0..23 66:168..191 => 31:0..23 66:192..215 => 35:0..23 66:216..239 => 39:0..23 66:240..263 => 43:0..23 66:264..287 => 47:0..23 66:288..311 => 51:0..23 66:312..335 => 55:0..23 66:336..359 => 59:0..23 66:360..383 => 63:0..23
E1 | Trunk 1: 2:0..29 => 67:0..29 Trunk 2: 6:0..29 => 67:30..59 Trunk 3: 10:0..29 => 67:60..89 Trunk 4: 14:0..29 => 67:90..119 Trunk 5: 18:0..29 => 67:120..149 Trunk 6: 22:0..29 => 67:150..179 Trunk 7: 26:0..29 => 67:180..209 Trunk 8: 30:0..29 => 67:210..239 Trunk 9: 34:0..29 => 67:240..269 Trunk 10: 38:0..29 => 67:270..299 Trunk 11: 42:0..29 => 67:300..329 Trunk 12: 46:0..29 => 67:330..359 Trunk 13: 50:0..29 => 67:360..389 Trunk 14: 54:0..29 => 67:390..409 Trunk 15: 58:0..29 => 67:410..439 Trunk 16: 62:0..29 => 67:440..479 | 66:0..29 => 3:0..29 66:30..59 => 7:0..29 66:60..89 => 11:0..29 66:90..119 => 15:0..29 66:120..149 => 19:0..29 66:150..179 => 23:0..29 66:180..209 => 27:0..29 66:210..239 => 31:0..29 66:240..269 => 35:0..29 66:270..299 => 39:0..29 66:300..329 => 43:0..29 66:330..359 => 47:0..29 66:360..389 => 51:0..29 66:390..409 => 55:0..29 66:410..439 => 59:0..29 66:440..479 => 63:0..29