Specifications

UHP-1000 SATELLITE ROUTER

INSTALLATION AND OPERATION MANUAL, V. 2.5

(SW VERSION 2.5.X)

 Decide where route it afterwards (to LAN) with VLAN tagging of this Table (or without tagging if the main

Table with VLAN=0 performed reception).

2.10.5 IP traffic screening

Satellite channels by nature are broadcasting. In this case in a point-to-multipoint topology network, IP-packets

transmitted to the satellite from Hub can be received on many terminals simultaneously. Since different networks

are routed to different terminals, it is logical that each SVLAN be assigned to a separate direction, and this is what

is usually done. But it may happen so that due to the router wrong configuration or in case of mixing routers traffic

into one SVLAN (e.g. into SVLAN 0 for a better channel efficiency), not all traffic received via SVLAN will be lead out

from the router to LAN (there will be no routes). If in this case the default route on the router is set to the Central

Station, a rooting loop may be generated, the result being that channels will be instantly overloaded with

circulating packets.

Figure 17 IP traffic screening

To avoid this situation, UHP-1000 router is provided with a special mechanism - IP screening. This mechanism

works as follows: each packet received from satellite gets a tag. If during routing this packet tries to go back to the

satellite it will be dropped. Packets coming from LAN and generated by the router itself are not tagged and they

have no limitations whatsoever.

ip screening auto|off|on - IP screening control

There are three modes of IP screening: AUTO, ON, OFF.

Automatic IP screening is active by default for the following modes of router operations: STAR Terminal, MESH

Terminal and HUBLESS Slave. This mechanism automatically disabled in modes: SCPC, HUB and HUBLESS Master

avoiding blockage of terminals-to-terminal traffic.

When IP screening is disabled (parameter OFF), this functionality is forcibly turned off for any mode of operation.

IP screening can be forcibly activated (parameter ON).

Router statistics (sh ip) is provided with a counter indicating how many packets have been dropped because of

screening.

Modulator

SCPC demodulator

ROUTER

Local IP

stack

LAN

ip map 0.0.0.0 /0 ml 0

SVLAN encapsulation

SVLAN decapsulation