A multilayer switch (MLS) is a computer networking device, that switches on OSI layer 2 like an ordinary network switch - and provides extra functions on higher OSI layers.
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2 Layer 7 switch, web-switch, content-switch 3 External addresses |
MultiLayer Switch (MLS) - OSI layer 3 and/or 4
A Multilayer Switch (MLS) can prioritize packets by the 6 bits in IP DSCP (differentiated services CodePoint). These 6 bits were used in the "old days" for Type of Service (ToS).
The following 4 mappings are normally available in a MLS:
- From OSI layer 2, 3 or 4 to IP DSCP (if IP packet) and/or VLAN IEEE 802.1p.
- From VLAN IEEE 802.1p to IP DSCP.
- From IP DSCP to VLAN IEEE 802.1p.
- From VLAN IEEE 802.1p to port queue.
Some MLS are also able to route between VLAN and/or portss like a common router. The routing are normally as quick as switching (with wirespeed).
Some of the applications areas are load-balancing among HTTP, HTTPS and/or VPN servers. Load-balancing can be made by using NAT. Some of the layer 7 switches can NAT at wirespeed.
Layer 7 switch, web-switch, content-switch
Some switches can use up to OSI layer 7 packet information, they are called layer 7 switches, content-switch or web-switch.
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External addresses