D-Link DSL-2640U user manual

Find out the following values from your ISP before you change them.

•VPI: Virtual Path Identifier. The valid range is 0 to 255.

•VCI: Virtual Channel Identifier. The valid range is 32 to 65535.

•Service Category: Five classes of traffic are listed—

oUBR Without PCR (Unspecified Bit Rate without Peak Cell Rate)— UBR service is suitable for applications that can tolerate variable delays and some cell losses. Applications suitable for UBR service include text/data/image transfer, messaging, distribution, and retrieval and also for remote terminal applications such as telecommuting.

oUBR With PCR (Unspecified Bit Rate with Peak Cell Rate)--

oCBR (Constant Bit Rate)—used by applications that require a fixed data rate that is continuously available during the connection time. It is commonly used for uncompressed audio and video information such as videoconferencing, interactive audio (telephony), audio / video distribution (e.g. television, distance learning, and pay-per- view), and audio / video retrieval (e.g. video-on-demand and audio library).

oNon Realtime VBR (Non-Real-time Variable Bit Rate)—can be used for data transfers that have critical response-time requirements such as airline reservations, banking transactions, and process monitoring.

oRealtime VBR (Real-time Variable Bit Rate)—used by time-sensitive applications such as real-time video. Rt-VBR service allows the network more flexibility than CBR.

•Quality of Service: Can be enabled only for UBR without PCR, UBR with PCR, and Non Realtime VPR.

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