HP StorageWorks Fabric OS 5.3.x administrator guide (5697-0244, November 2009)

Fabric OS 5.3.0 administrator guide 397
Port Numbering on the 400 MP Router
You do not need to specify slot numbers for the 400 MP Router. Refer to the GbE ports as ge0 and ge1,
and the Fibre Channel ports are numbered 0 through 15. Moving from left to right on the front of the
chassis, the sixteen Fibre Channel ports, followed by the 2 GbE ports.
You manage the 400 MP Router as if it had 32 Fibre Channel ports (16 standard Fibre Channel ports, and
16 virtual Fibre Channel Ports) and 2 GbE ports. Specify port addresses using the slot and port numbers.
For example, to disable VE_Port 18 on slot 1, use portDisable 1/18. To disable GbE port 1 on slot 1,
use portDisable 1/ge1.
Figure 30 400 MP Router port numbering
Tunneling and Qos policies
Quality of Service (QoS) refers to policies for handling differences in data traffic. These policies are based
on data characteristics and delivery requirements. For example, ordinary data traffic is tolerant of delays
and dropped packets, but voice and video data are not. QoS policies provide a framework for
accommodating these differences in data as it passes through a network.
Layer three DiffServ Code Points (DSCP)
Layer three class of service DiffServ Code Points (DSCP) refers to a specific IEEE 802.1p VLAN tag priority
implementation for establishing QoS policies. DSCP uses six bits of the Type of Service (TOS) field in the
802.1p header, which allows up to 64 different values to associate with data traffic priority.
DSCP settings are useful only if IP routers are configured to enforce QoS policies uniformly within the
network. IP routers use the DSCP value as an index into a Per Hop Behavior (PHB) table. Control
connections and data connections may be configured with different DSCP values. Before configuring DSCP
settings, determine if the IP network you are using implements PHB, and consult with the network
administrator to determine the appropriate DSCP values.
An older prioritization scheme (sometimes called Layer Two Class of Service, or CoS), used only the upper
three bits of the TOS field, allowing eight priorities. If the IP network you are using has implemented this
scheme, Table 98 may be of use in mapping CoS priorities to DSCP priorities when consulting with the
network administrator.
GbE0 GbE1FC0 FC15
Table 98 Mapping CoS priorities to DSCP priorities
CoS priority/bits DSCP priority/bits
0 / 000 0 / 000000
1 / 001 8 / 001000
2 / 010 16 / 010000
3 / 011 24 / 0110 00
4 / 100 32 / 100000
5 / 101 40 / 101000
6 / 110 48 / 110000
7 / 111 5 6 / 1110 0 0