TANDBERG D13187-03 - Manual (Page 61)

TANDBERG Gateway
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Appendices
Appendix 3: Capacity
Gateway capacity - calculation
The total capacity in the gateway is defined by the following rules:
1) A maximum of 8 video calls and 8 telephone calls.
2) Software version defines maximum ISDN bandwidth:
2 Mbps -> Maximum ISDN bandwidth is 1920 kbps (30x64 kbps).
4 Mbps -> Maximum ISDN bandwidth is 3840 kbps (60x64 kbps).
3) In addition, each call has a weight depending on bandwidth/encryption:
Bandwidth Teleph. 64 128 192 256 320 384 512 768 1152 1472 1920
Non-encr. 22 74 80 82 84 88 92 108 124 160 176 220
Encrypted N/A 106 118 120 122 136 146 168 222 N/A N/A N/A
The sum of the call weights cannot exceed 845 and max. bandwidth. Users will be prevented from setting up calls that
exceeds these limits.
When encryption mode is set to Independent, the Gateway calls may be weighted as encrypted calls even though on side
of the connection might not be encrypted.
Example (4 Mbps version):
If the gateway has made 3 calls at 768, 2 calls at 384, and 2 encrypted calls at 192 the calculation will be:
3x124 + 2x92 + 2x120 = 372 + 184 + 240 = 796. Since 796 is less than 845 and the total bandwidth 3456 kbps, do not
exceed the maximum bandwidth limit, this will be possible.
Gateway capacity – typical scenarios (4 Mbps version)
Below some typical capacity scenarios are listed. They can be derived by the calculation above:
Bandwidth Non-encrypted Encrypted
128 kbps 8+8* 7+0
256 kbps 8+7 6+5**
384 kbps 8+4 5+5
512 kbps 7+4 5+0
768 kbps 5+0 3+8
1472 kbps (1.5 Mbps) 2+8 N/A
1920 kbps (2 Mbps) 2+0 N/A
* 8+8 indicates 8 video calls and 8 telephone calls.
** 6+5 indicates 6 encrypted video calls and 5 unencrypted telephone calls.