ZyXEL p-2302hw-p1 Manual Do Utilizador
P-2302HW/HWL-P1 Series User’s Guide
Chapter 9 SIP
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9.1.10 MWI (Message Waiting Indication)
Enable Message Waiting Indication (MWI) enables your phone to give you a message–waiting
(beeping) dial tone when you have one or more voice messages. Your VoIP service provider
must have a messaging system that sends message-waiting-status SIP packets as defined in
RFC 3842.
(beeping) dial tone when you have one or more voice messages. Your VoIP service provider
must have a messaging system that sends message-waiting-status SIP packets as defined in
RFC 3842.
9.1.11 Quality of Service (QoS)
Quality of Service (QoS) refers to both a network's ability to deliver data with minimum delay
and the networking methods used to provide bandwidth for real-time multimedia applications.
and the networking methods used to provide bandwidth for real-time multimedia applications.
9.1.11.1 Type of Service (ToS)
Network traffic can be classified by setting the ToS (Type Of Service) values at the data source
(for example, at the ZyXEL Device) so a server can decide the best method of delivery, that is
the least cost, fastest route and so on.
(for example, at the ZyXEL Device) so a server can decide the best method of delivery, that is
the least cost, fastest route and so on.
9.1.11.2 DiffServ
DiffServ is a class of service (CoS) model that marks packets so that they receive specific per-
hop treatment at DiffServ-compliant network devices along the route based on the application
types and traffic flow. Packets are marked with DiffServ Code Points (DSCPs) indicating the
level of service desired. This allows the intermediary DiffServ-compliant network devices to
handle the packets differently depending on the code points without the need to negotiate paths
or remember state information for every flow. In addition, applications do not have to request
a particular service or give advanced notice of where the traffic is going.
hop treatment at DiffServ-compliant network devices along the route based on the application
types and traffic flow. Packets are marked with DiffServ Code Points (DSCPs) indicating the
level of service desired. This allows the intermediary DiffServ-compliant network devices to
handle the packets differently depending on the code points without the need to negotiate paths
or remember state information for every flow. In addition, applications do not have to request
a particular service or give advanced notice of where the traffic is going.
1
9.1.11.3 DSCP and Per-Hop Behavior
DiffServ defines a new DS (Differentiated Services) field to replace the Type of Service (TOS)
field in the IP header. The DS field contains a 2-bit unused field and a 6-bit DSCP field which
can define up to 64 service levels. The following figure illustrates the DS field.
field in the IP header. The DS field contains a 2-bit unused field and a 6-bit DSCP field which
can define up to 64 service levels. The following figure illustrates the DS field.
Figure 75 DiffServ: Differentiated Service Field
DSCP is backward compatible with the three precedence bits in the ToS octet so that non-
DiffServ compliant, ToS-enabled network device will not conflict with the DSCP mapping.
DiffServ compliant, ToS-enabled network device will not conflict with the DSCP mapping.
1.
The ZyXEL Device does not support DiffServ at the time of writing.
DSCP
(6-bit)
Unused
(2-bit)