Specifications
Engineering Guidelines
170
Before determining the bandwidth for particular links, it is important to consider the traffic flow
and where devices are located relative to their controllers. The use of compression zones and
IP networking also have a bearing on traffic flow in parts of the network.
See “Network Configuration Concepts” on page 191 for details on bandwidth requirements for
different LAN and WAN links with and without compression.
For bandwidth requirements for TFTP servers and connections to end devices refer to the
section “3300 TFTP Server” on page 245."
SDS is used to share system information around the network. The SDS protocol runs on TCP
and the bandwidth consumed is determined dynamically by the TCP protocol.
SDS information contains many components and has both sustained and peak data transfer
rates. SDS has been proven to work with link speeds as low as 100kbits/s. For minimal impact
a minimum bandwidth of 300kbits/s is recommended. To handle the occasional peak burst a
connection of 100Mbits/s is ideal. Where this higher bandwidth is not available, e.g. WAN link,
the TCP protocol will adjust the data rate to match the available bandwidth. In this case, some
data may transfer at a slower rate.
Note that SDS only shares data between systems when there are configuration changes to the
system. These can occur manually, or through tool automation, but generally require some
management activity to start the process. As such, the suggested bandwidths are not consumed
on a continual basis, but only as needed; i.e. when SDS is activated to share information. The
suggested rates are only recommended rates to maintain expected responsiveness, rather
than as a value that needs to be continually reserved.
cPPP 10ms 72.0 48.0 40.0
20ms 68.0 28.0 36.0
30ms 66.7 21.3 34.7
40ms 66.0 10.0 34.0
VoATM (AAL5, IP) 10ms 127.2 84.8 84.8
20ms 106.0 42.4 63.6
30ms 98.9 28.3 56.5
40ms 84.8 21.2 53.0
PPPoEoA 10ms 169.6 84.8 127.2
20ms 106.0 63.6 84.8
30ms 98.9 42.4 70.7
40ms 95.4 31.8 53.0
Table 48: Other Protocols: On-the-wire Bandwidth (continued)
Codec: G.711 G.729 G.722.1
Payload: 64kbits/ 8kbit/s 32kbit/s
Link Type Packet Rate (ms) Wire (kbits/s) Wire (kbits/s) Wire (kbits/s)
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