SonicWALL 5.8.1 Manuale Utente

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Firewall Settings > QoS Mapping
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SonicOS 5.8.1 Administrator Guide
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Token Based CBQ – An enhancement to CBQ that employs a token, or a credit-based 
system that helps to smooth or normalize link utilization, avoiding burstiness as well as 
under-utilization. Employed by SonicOS’ BWM.
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RSVP – Resource Reservation Protocol. An IntServ signaling protocol employed by some 
applications where the anticipated need for network behavior (e.g. delay and bandwidth) is 
requested so that it can be reserved along the network path. Setting up this Reservation 
Path requires that each hop along the way be RSVP capable, and that each agrees to 
reserve the requested resources. This system of QoS is comparatively resource intensive, 
since it requires each hop to maintain state on existing flows. Although IntServ’s RSVP is 
quite different from DiffServ’s DSCP, the two can interoperate. RSVP is not supported by 
SonicOS.
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Shaping – An attempt by a QoS system to modify the rate of traffic flow, usually by 
employing some feedback mechanism to the sender. The most common example of this is 
TCP rate manipulation, where acknowledgements (ACKs) sent back to a TCP sender are 
queued and delayed so as to increase the calculated round-trip time (RTT), leveraging the 
inherent behavior of TCP to force the sender to slow the rate at which it sends data. 
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Type of Service (ToS) – A field within the IP header wherein CoS information can be 
specified. Historically used, albeit somewhat rarely, in conjunction with IP precedence bits 
to define CoS. The ToS field is now rather commonly used by DiffServ’s code point values.