EASTAR UHP-1000 SERIES SATELLITE ROUTER
INSTALLATION AND OPERATION MANUAL, V. 2.3
(SW VERSION 2.2.9)
© ROMANTIS 2010
38
www.romantis.com
UHP# sh rt
Transmit --------------------------------------------------
Source_IP Destination_IP Plt Errors
10.0.0.17 10.1.0.1 11 0
Receive --------------------------------------------------
Source_IP Port Destination_IP Port TOS Plt Packets Errors
10.1.0.1 4001 10.0.0.17 16011 0 11 1171 3
Statistics show addresses, UDP ports, Payload Type and packets TOS. Errors counter
increases as packets are lost also in other cases when it is impossible to decode the packet
compressed heading.
2.9
Traffic Shaper
Traffic shaper (TS) is intended for adjustment of the bandwidth occupied by data streams in
transmitting via a satellite. TS is based on the streams concept – controlled ―pipes‖ for
traffic between router and modulator. Each stream is provided with three priority queues
and a ―hard‖ limitation in the traffic rate at the output, i.e. the stream behaves practically in
the same way as a modulator. Prioritization of the stream queues is also adhered to.
Packets from output streams arrive in the modulator queues with the same priorities
(packets from LOW queue of TS arrive in the LOW queue of the modulator, etc.). Altogether
there are 500 streams.
Each map-record in the route Table can allow traffic via some of the TS streams. One
stream can accept traffic from different networks using several records including those with
different SVLANs. If stream number is not specified on map-records, then their traffic goes
via stream 0. By default, bandwidth of this stream is set to maximum. If the bandwidth is
set to a lower value and it will be forgotten, a rather strange, at first sight, modulator
behavior may be observed – when the channel is not loaded but traffic cannot fully occupy
it.
If the rate of traffic entering the stream is greater than the stream bandwidth at the given
moment then traffic is buffered to create delay during transmission.
Basic principles of TS operation:
Tailoring committed information rate (CIR) for each stream
If there is a free bandwidth on the modulator and streams are allowed to exceed
CIR, TS will extend bandwidths of those streams that are overloaded
Expansion proportional to CIR
Expansion of streams is effected smoothly, proportionally to the free bandwidth of
the modulator so as to avoid overloads, narrowing is effected more aggressively
based on the same reason
If modulator load approaches its limit, TS narrows the bandwidths of exceeding
streams to lower the modulator load or to the values of their CIRs
Calculation and correction of the stream bandwidths is made every second, and that is
why TS responds dynamically to the behavior and requirements of the network.
IP Router
Low
Med
High
.
.
.
Stream 0
Stream 1
Stream 2
Stream N
Transmit
Bandwidth
calculator
Delay
Load
Modulator
ip map ...
