Datastream

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See also data stream.

Datastream is the name of a type of broadband network connection in the United Kingdom. Datastream is a wholesale product in which the wholesale customer can purchase connectivity between their own point of presence and a number of end users.

[edit] Technical details

The connections between the end users and the OLO (the wholesale customer of the DataStream product) are provided in three parts.

BT provides connectivity between the end user and the nearest BT Serving Exchange via ADSL. As of writing this, this end user access line can have a bandwidth ranging between 288Kbit/s and 8128Kbit/s downstream and up to 448Kbit/s upstream.

For each serving exchange involved in providing end user access lines, a virtual path is provisioned to a BT ATM switch on BT's "core network." One or more DSLAMs at the serving exchange combine the traffic from the end user access lines for delivery to the ATM switch.

From the BT switch, the traffic from the various virtual paths is combined and an ATM Customer Access Link (CAL) is used to connect to the NTE at the wholesale customer's point of presence.

[edit] Comparison to IPStream and LLU

IPStream, DataStream, and LLU are all products that can be used for the delivery of bit-stream products, but represent different degrees of involvement from BT. In the case of LLU, the OLO has direct access to the twisted pair delivered to the end-user's NTE and has near total control of the connection from end-to-end. With DataStream, BT still manages the DSL multiplexing equipment at the various local exchanges, and hands off the aggregated traffic to the OLO at one or a few points of presence. With IPStream, BT also provides the IP transport services.