Six Quarks

The Six Quarks V

Measured Parameters

Basic measurement principles

Six Quarks SQ probes have software modules - quality agents that implement different types of tests. Presently the following quality assurance agents are available:

Six Quarks is constantly working on extending the list of available agents, so new quality agents are likely to come into service.

Ethernet OAM Agent

Ethernet OAM quality assurance agent controls channel quality, in conformity with ITU-T Y.1731. The response party may be any device supporting Ethernet OAM tests as provided by ITU-T Y.1731 specification. Two types of tests are maintained: one-way (ETH-LB) and two-way (ETH-DM).

Ethernet OAM measurements

The following parameters are available for assurance:

For ETH-DM tests the following parameters are also available:

Echo-test Agent

Echo-test agent makes measurements on the network layer generating test traffic and forwarding it to any third party device that supports traffic mirroring using the ICMP, UDP or TCP protocols. The external device sends received traffic back to Six Quarks SQ probe where echo-test agent receives and analyses it.


The following parameters are available for assurance:

Network Quality Assurance Agent

Network detailed quality assurance agent makes measurements (as the echo-test agent does) on the network layer but unlike the echo-test agent, which monitors basic parameters only, the network quality agent provides detailed information of the network quality.

The agent establishes a control connection with the agent on an other Six Quarks SQ probe. After that it generates test traffic and forwards it to the neighbouring probe. The probe that receives test traffic analyses it, then forms and sends response test traffic. After measurement session is over, agents exchange test results via control channel and compose the overall picture of the assured network quality.

Detailed network quality control

The following parameters are available for assurance:

Network Applications Quality Assurance Agent

Network applications quality assurance agent assesses customers' contentment with standard network applications. It is often the only instrument allowing to detect reasons of users' dissatisfaction when overall network quality level is acceptable. The agent controls quality of access to specific network services: clock synchronization (NTP), domain names resolution (DNS) and any network service running on a TCP port, for instance: HTTP, FTP or SSH server.

When making tests the network applications quality assurance agent connects to an existing application server as its client. After the session is over the agent creates a report on its quality.

Network applications quality assurance

The following parameters are available for assurance:

Besides, the following parameters are available for DNS service control:

The following parameters are also available for NTP service control:

Voice over IP Delivery Quality Agent

VoIP delivery quality assurance agent creates control connection to a responding VoIP agent functioning on another Six Quarks SQ probe. After establishing control channel the first agent creates synthetic media traffic according to the selected codec and sends it to the recipient probe. The responding probe, in its turn, also creates synthetic media traffic according to the selected codec. In the end of session agents analyse session results.

VoIP quality assurance

The following parameters are available for assurance:

IPTV Quality Agent

IPTV quality assurance agent controls IPTV image quality using 92 metrics. The IPTV quality agent of Six Quarks SQ probe joins a multicast group. After that it analyses deeply the received MPEG-stream.

IPTV quality assurance

IPTV quality agent examines SPTS and MPTS transport streams, analyses their structure, elementary streams, identifying MPEG2, MPEG4, AVC video codecs and MPEG1, MPEG2 layer 1,2,3, AC3 audio codecs.

Quality parameters are analysed and controlled in conformity with the following protocols and recommendations:

92 metrics are analysed and controlled at the following levels: