User manual

Conguring Quality of Service

A.2 Trac Shaping

200

Policy

Select a QoS policy from the drop-down menu. Options include Priority, FIFO

(First In, First Out), Fairness (balanced set), RED (Random Early Detection), and

WRR (Weighted Round Robin).

When should this rule occur?

By default, the rule will always be active. However, scheduler rules can be

configured to define time periods during which the rule is active. To learn how

to configure scheduler rules, see the “Advanced Settings” chapter.

A.2c Ingress Data

The FiOS Router can control outgoing data fairly easily. It can queue packets,

delay them, give precedence to other packets, or drop them. This helps in

resolving upload (Tx) traffic bottlenecks, and in most cases is sufficient. However,

in the case of download (Rx) traffic bottlenecks, the ability to control the flow is

much more limited. The FiOS Router cannot queue packets, since in most cases

the local network (LAN) is much faster than the Internet (WAN), and when the

FiOS Router receives a packet from the Internet, it passes it immediately to the

local network.

QoS for ingress data has the following limitations, which do not exist for

outgoing data:

QoS can only be applied to TCP streams (UDP streams cannot be delayed);t

no borrowing mechanism;t

and when reserving Rx bandwidth, it is strictly taken from the bandwidth of t

all other classes.

Furthermore, the FiOS Router cannot control the behavior of the ISP, which may

not have proper QoS handling. Unfortunately, this is a common situation. Let’s

look at a scenario of downloading a large file and surfing the Internet at the

same time. Downloading the file is distinguished by small requests, followed

by very large responses. This may result in blocking HTML traffic at the ISP.

A solution for such a situation is limiting the bandwidth of low-priority TCP

connections (such as the file download).