RUTX11 Traffic Shaping

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The information in this page is updated in accordance with firmware version RUTX_R_00.07.22.1.

Summary

Traffic Shaping is a bandwidth management technique used on computer networks which delays some or all datagrams to bring them into compliance with a desired traffic profile. Traffic Shaping is used to optimize or guarantee performance, improve latency, or increase usable bandwidth for some kinds of packets by delaying other kinds.
This manual page provides an overview of the Traffic Shaping pages in RUTX11 devices.

SQM

The SQM page is used to set up Smart Queue Management (SQM) instances which can limit the download and upload speeds of selected network interfaces.
Note: For SQM to properly work "Software flow offloading" needs to be turned off on this device. This can be done in Network → Routing/NAT Offloading settings.
The Smart Queue Management section contains a list of existing SQM instances and can be used manage them (edit/delete/enable/disable). By default the list is empty:
To add a new instance and begin editing, look below to the Add New Instance section and:
  1. enter a custom name in the 'Name' field;
  2. click the 'Add' button;
  3. configuration window will open automatically.
Refer to the sections below for information on editing SQM instances.

General Setup

The General Setup section is used to set download and upload speed limits for a selected network interface.
FieldValueDescription
Enabledoff | on; default: offTurns the SQM configuration on or off.
Interface namenetwork interface; default: br-lan (lan)Selects to which interface this SQM configuration will apply. Additional note: consider reading the Additional notes section before limiting speeds on selected interfaces.
Download speed (kbit/s)integer [0..2147483647]; default: noneLimits the download speed (ingress) of the selected interface to the value specified in this field.
Upload speed (kbit/s)integer [0..2147483647]; default: noneLimits the upload speed (egress) of the selected interface to the value specified in this field.

Advanced Settings

The Advanced Settings section describes the internal logic of the SQM configuration.
FieldValueDescription
Queuing disciplines usable on this systemcake | fq_codel; default: cakeQueue management logic type. Look to the row below for detailed information.
Queue setup scriptlayer_cake.qos | piece_of_cake.qos | simple.qos | simplest.qos | simplest_tbf.qos; default: piece_of_cake.qosDescribes the queue management logic.
  • cake
    • layer_cake.qos - uses the cake qdisc as a replacement for both htb as shaper and fq_codel as leaf qdisc. This exercises cake's diffserv profile(s) as different "layers" of priority.
    • piece_of_cake.qos - uses the cake qdisc as a replacement for both htb as shaper and fq_codel as leaf qdisc. It just does not come any simpler than this, in other words it truly is a "piece of cake".
  • fq_codel
    • simple.qos - BW-limited three-tier prioritisation scheme with your qdisc on each queue.
    • simplest.qos - simplest possible configuration: HTB rate limiter with your qdisc attached.
    • simplest_tbf.qos - simplest possible configuration (TBF): TBF rate limiter with your qdisc attached. TBF may give better performance than HTB on some architectures.

Additional notes

Please consider that limiting the speed of certain interfaces may limit the speed of other interfaces as well. For example, if you limit the download and upload speeds of the default LAN interface (br-lan) to 50 000 kbps (50 Mbps) this will affect the speeds between:
  • Ethernet LAN machines (including the device)
  • Ethernet LAN machines and WAN*
  • WiFi devices**
  • Wifi devices and LAN machines**
  • WiFi devices and WAN**
* Since LAN machines communicate with WAN servers over the device which is also considered a LAN machine, LAN-to-WAN and WAN-to-LAN speeds are also affected.
** By default, wireless network interfaces are attached to the default Ethernet LAN network (br-lan). If you wish for WiFi speeds to remain unaffected, consider creating an additional Ethernet interface and attach your WiFi interfaces to it. This can done in the following WebUI pages:
  • Network → Interfaces (to create an additional network interface)
  • Network → Wireless (to attach WiFi interfaces to Ethernet interfaces)
The table below demonstrates speed changes between some of the main default network interfaces if br-lan speed is set to 50 Mbps.
Ethernet LANWiFi LANEthernet WANMobile WAN
Ethernet LAN50505050
WiFi LAN50505050
Ethernet WAN5050unchangedunchanged
Mobile WAN5050unchangedunchanged
Changing the speeds of other network interfaces may also affect more than one interface. However, the Ethernet LAN interface (br-lan) is related to most interfaces. Therefore, it is advised to limit the speeds of other interfaces in order to achieve more precise results (unless, of course, your goal to is to limit the speed of br-lan).
Another example to consider is limiting WAN interface speeds since that is the most widely implemented use case and affects less interface-to-interface relationships. For instance, limiting Ethernet WAN (eth1) speed to 50 Mbps would produce the following results:
Ethernet LANWiFi LANEthernet WANMobile WAN
Ethernet LANunchangedunchanged50unchanged
WiFi LANunchangedunchanged50unchanged
Ethernet WAN5050unchangedunchanged
Mobile WANunchangedunchangedunchangedunchanged
Please take caution when using SQM to limit speeds in order to avoid unexpected results.

QoS

QoS provides the possibility to prioritize network traffic based on hosts, ports or services and limit download & upload speeds on a selected interface.
This chapter of the user manual provides an overview of the QoS page in RUTX11 devices.
Note: For QoS to properly work "Software flow offloading" needs to be turned off on this device. This can be done in Network → Routing/NAT Offloading settings. Note: QoS is additional software that can be installed from the System → Package Manager page.

Interfaces

The Interfaces section is used to set up download and upload speed limits on the device's network interfaces.
FieldValueDescription
Interface namewan | lan| mobile (interface); default: lanDecreases upload and download ratio to prevent link saturation.
Calculate overheadyes | no; default: noDecreases upload and download ratio to prevent link saturation.
Download speed (kbit/s)integer; default: 1024Maximum download speed for the specified interface.
Upload speed (kbit/s)integer; default: 128Maximum upload speed for the specified interface.
Enableyes | no; default: noTurns the rule on or off.
Actions- (interactive button); default: DeleteDeletes instance.

Classification Rules

The Classification Rules section is used to configure rules that prioritize certain traffic over other, less important traffic. This traffic can be defined by a source or destination host, port or a network protocol. Traffic that matches a rule with higher preference will be handled with higher priority.
Generally, this should be used in cases where you want to isolate certain types of traffic in order to make sure the RUTX11 is handling more important traffic (for example, video streaming, SSH) at a higher priority and less important traffic (FTP, HTTP) at a lower priority.
FieldValueDescription
TargetPriority | Express | Normal | Bulk; default: NormalDefines the priority of handling the type of traffic defined in this rule.
Source hostAll | IP from the list | + Add new; default: AllPackets matching this source host(s) (single IP or in CIDR notation) belong to the bucket defined in target.
Destination hostAll | IP from the list | + Add new; default: AllPackets matching this destination host(s) (single IP or in CIDR notation) belong to the bucket defined in the target.
ProtocolAll | TCP | UDP | ICMP | -- Custom --; default: AllData transmission protocol to match the rule.
PortsAll | integer [1..65535]; default: nonePort number(s) to match the rule. You can enter multiple ports by separating them by commas (e.g., 22,53,80).
Actions- (interactive button); default: DeleteDeletes instance.