RNP > Technologies > QoS > QoS at RNP

QoS at RNP

In 2001, RNP assembled a QoS pilot network involving the Points of Presence (PoPs) in Distrito Federal, Minas Gerais, São Paulo, Rio de Janeiro and Rio Grande do Sul. Its main goals were getting knowledge on QoS architecture and experience implementing differentiated services in the routers of RNP2 backbone. The project of the pilot network was extended until November 2001.

The greatest emphasis was given to real-time multimedia applications, such as videoconference and video/audio streaming. It was decided that QoS would be implanted through the Premium Service configuration (Expedited Forwarding or Virtual Leased Line) for applications needing reduced loss, little delay and little delay variation (jitter), and Assured Forwarding, for applications demanding greater reliability than the one provided by the best-effort service. The Assured Forwarding Service, also known as the Olympic Service, grants the user a band percentage, even in case of jams. It is divided into the Gold, Silver and Bronze categories, implying a greater or smaller percentage, according to the category adopted. In the rest of the band, the best-effort was used.

The evaluation parameters were:

• throughput; and
• package loss.

The traffic monitoring and generation tools were:

• Tangram;
• MGen; and
• Rude & Crude.

Architecture:

• Diffserv

At the end of the project, some problems were detected in routers when they ran multiple services at the same time. After all, since RNP is committed to innovation, it tested very modern versions of systems in the routers, which were not completely stable yet. A document was produced about the results of everything that was done in the pilot network. The experience also resulted in a proposal, currently being analyzed, to implement QoS in the entire RNP2 backbone, according to demands. In this initiative, the collaboration of the QoS Working Group (GT QoS) will be of paramount importance. This Working Group, formed in 2002 and continuing until 2003, will define the architecture to be adopted in the backbone.