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BayStack 450 10/100/1000 Series Switches
IEEE 802.1p Prioritizing
You can use the VLAN Configuration screens to prioritize the order in which the switch forwards packets, on a
Before
CRC
PVID = 2
Priority = 6
Data
Port configuration parameters
SA | Port 1 | Port 2 | Port 3 |
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| Tagged member |
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| of VLAN 2 (Port 5) |
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DA | 802.1Q Switch |
| High |
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Port 5 |
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| 4 |
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| 5 |
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| Port | CRC* | Data | Tag | SA | DA |
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| queue |
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| Low | (*Recalculated) |
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| Port 6 | Port 7 | Port 8 |
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Untagged member | CRC | ||
of VLAN 2 | |||
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| Data | |
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Outgoing | SA | ||
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untagged packet DA | |||
(unchanged) |
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| 8100 |
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| Priority = 6 |
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| CFI |
| VID = 2 |
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| 16 bits |
| 3 bits |
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| 1 bit |
| 12 bits |
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| After |
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Key |
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Priority | - User_priority |
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CFI | - Canonical format indicator |
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VID | - VLAN identifier |
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BS45024A
Figure 1-34. Prioritizing Packets
The newly tagged frame is read within the switch and sent to the port’s high or low transmit queue for disposition (see Figure
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