SatLink VSAT User Guide
Publication no. 101557
Copyright © 2009 – STM Group, Inc.
Page 93 (160)
# ip set 12 10.10.22.1 255.255.255.0
Finally, associate a GRE tunnel to each of the VLAN interfaces. This causes the IP address of the
respective VLAN interface to be set as the tunnel source IP address of the respective GRE tunnel.
#ip gre add 192.168.1.0 255.255.255.0 10.20.1.1 11
#ip gre add 192.168.2.0 255.255.255.0 10.20.1.2 12
#ip gre show
GRE Tunnel Interfaces:
----------------------
If Tunnel Local Address Tunnel Remote Address
4 10.10.21.1 10.10.20.1
5 10.10.21.2 10.10.20.2
It is assumed that the other endpoint of each of the GRE tunnels maps back to the respective VLAN
interface IP addresses as the tunnel destination. The address spaces of the two GRE tunnels are
independent as they connect to different VLANs, and they may be overlapping.
18.7 Ethernet User Priority (802.1p/D)
IEEE Std 802.1Q defines an Ethernet frame format that can be used to carry user priority across a LAN.
IEEE Std 802.1p/D describes how user priority can be used to control queuing delay in an Ethernet MAC
bridge. In a similar way, the STM SatLink VSAT can control queuing delay before transmission to the
satellite, based on the user priority tag values and the chosen mapping to QoS groups. When the STM
SatLink VSAT is licensed to support VLAN extension the VSAT is also capable of mapping user priority
tag values to QoS groups. However, the interface must be in VLAN trunk mode to receive user priority,
as described in section 18.6.
By default, the user priority does not affect the choice of QoS group and the packets are subject to
inspection by the MFC. As required, the VSAT can be configured to map a specific user priority tag
value to a specific QoS group. This effectively bypasses the IP header inspection, classification and
mapping offered by the MFC. Untagged frames are always forwarded to the MFC. Make sure that the
Ethernet interfaces connected to the STM SatLink VSAT operate in VLAN trunk mode (802.1Q) and
provides correct user priority tag values.
Note that the STM SatLink network is an IP network and not an Ethernet MAC bridge and thus the user
priority value will not be regenerated at the egress of the SatLink network.
Let’s say that user wants to implement a “scavenger class” for e.g. peer-to-peer traffic and a best effort
class for normal traffic, based on Ethernet user priority:
First, set the Ethernet in VLAN trunk mode and allow traffic on applicable VLAN IDs:
# eth vlan 0
Here it is assumed that all traffic is going on the single VLAN ID 0 e.g. being the default VLAN of the
LAN. Further, the user priority tag values are mapped to QoS groups:
# eth primap 0 6 maps default user priority to internal critical data (becoming external
best effort)
# eth primap 1 0 maps user priority 1 down to internal best effort (becoming scavenger)
# eth primap 2 0 maps user priority 2 down to internal best effort (becoming scavenger)
To Next Page
Loading...
