P-2002 Series User’s Guide

64

Chapter 6 VoIP Screens

6.5  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. 

6.5.1  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 Prestige) so a server can decide the best method of delivery, that is 
the least cost, fastest route and so on. 

6.5.2  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.

1

Fax Option

Use this field to set how the Prestige handles fax messages. You can select either 

the 

Fax Pass-through 

or the 

T.38

 fax methods. 

Select 

Fax Pass-through

 to have the Prestige send fax messages over G.711. 

The peer devices must also use G.711. 
Select 

T.38

 to have the Prestige send fax messages over the IP network as UDP 

or TCP/IP packets. It provides better transmission quality than fax pass-through 

but may have inter operability problems. The peer devices must also use T.38.

Call Forward 

Table

Select which call forwarding table you want the Prestige to use to block or redirect 

calls. You can use a different call forwarding table for each SIP account or use the 

same call forwarding table for both.

Caller Ringing

Select the 

Enable

 check box to activate a custom caller ringing tone for incoming 

calls. The caller ringing tone is the sound that incoming callers will hear when they 

call you. Use the 

Caller Ringing Tone 

drop-down list box to choose a tone. 

The caller ringing tone currently works with calls that are using the G.729 codec.

On Hold

Select the 

Enable

 check box to activate a custom on hold tone for callers on hold. 

The on hold tone is the sound callers will hear when you put them on hold. Use the 

On Hold Tone 

drop-down list box to choose a tone.

The on hold tone currently works with calls that are using the G.729 codec.

Back

Click

 Back

 to return to the VoIP screen without saving configuration changes.

Apply

Click 

Apply

 to save your changes back to the Prestige.

Reset

Click 

Reset

 to begin configuring this screen afresh.

Table 13   

VoIP Advanced (continued)

LABEL

DESCRIPTION

1.

The Prestige does not support DiffServ at the time of writing.