See also data stream

Data stream

In telecommunications and computing, a data stream is a sequence of digitally encoded coherent signals used to transmit or receive information that is in the process of being transmitted....

.

Datastream is the name of a type of broadband network connection in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. 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.

Technical details

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

1. BT provides connectivity between the end user and the nearest BT Serving Exchange via ADSL, SDSL
   Symmetric Digital Subscriber Line
   Symmetric digital subscriber line can have two meanings:* In the wider sense it is a collection of Internet access technologies based on DSL that offer symmetric bandwidth upstream and downstream...
   
   , and FTTX
   FTTX
   Fiber to the x is a generic term for any broadband network architecture using optical fiber to replace all or part of the usual metal local loop used for last mile telecommunications...
   
   . As of writing this, this end user access line can have a bandwidth ranging between 288 kbit/s and 8,128 kbit/s (8 Mibit/s) downstream and up to 832 kbit/s upstream for ADSL, and up to 2048 kbit/s (2 Mibit/s) for SDSL. For Fibre based connections, speeds can be as high as 100Mbit/s although most connections of this type are fibre from exchange to cabinet so therefore limited to a maximum of 40Mbit/s.
2. 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. A virtual path can range in size from 250 kbit/s to 34 Mbit/s. One or more DSLAMs at the serving exchange combine the traffic from the end user access lines for delivery to the ATM switch.
3. 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 Network Terminating Equipment (NTE) at the wholesale customer's point of presence.

Comparison to IPStream and LLU

IPStream

Ipstream

IPstream is the most highly-used wholesale broadband Internet service in the United Kingdom. BT Wholesale sells the service to ISPs and IPTV providers, who use it to provide ADSL services to customers over Openreach telephone lines....

, DataStream, and local loop unbundling

Local loop unbundling

Local loop unbundling is the regulatory process of allowing multiple telecommunications operators to use connections from the telephone exchange to the customer's premises...

 (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

Network termination

A network termination is a device that connects the customer's data or telephone equipment to a carrier's line that comes into a building or an office...

 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

External links

• Technical Information on Datastream from thinkbroadband.com
• Conditions for BT Datastream Service from BT
• Datastream Technology Management IT Services Firm headquartered in Glendale, CA unrelated to topic of this article