Nortel BayStack 380, Инструкция по использованию, Страница: 71 / 218

Chapter 2 Network configuration 71
Using the BayStack 380 10/100/1000 Switch
IEEE 802.1p Prioritizing
You can use the VLAN Configuration screens to prioritize the order in which the
switch forwards packets, on a per-port basis. For example, if messages from a
specific segment are crucial to your operation, you can set the switch port
connected to that segment to a higher priority level (by default, all switch ports are
set to Low priority). When the switch receives untagged packets on that port, the
untagged packets are tagged according to the priority level that you assign to the
port.
Figure 26 Prioritizing packets
10545EA
CRC
Port 1 Port 2 Port 3
High
Low
Port 6
Po
rt
4
Port 7 Port 8
PVID = 2
Priority = 6
Port configuration
parameters
Key
Priority
CFI
VID - User_priority
- Canonical format indicator
- VLAN identifier
Tagged member
of VLAN 2 (Port 5)
(*Recalculated)
Before
Untagged member
of VLAN 2
Port 5
transmit
queue
Outgoing
untagged packet
(unchanged)
Data
SA
DA
CRC
CRC*
810D Priority = 6 CFI VID = 2
16 bits 3 bits
After
1 bit 12 bits
Data Tag SA DA
Data
SA
DA
Po
rt
5