Access Technologies

Customers’ sites can be connected into an 8el Wide Area Network using a variety of different access technologies. Each technology has characteristics which determine its suitability within each tailored design.

The following access technologies are not circuit provider specific and can be delivered into the 8el core based upon design and not constraint.

ISDN

8el typically deploy ISDN as a backup solution. ISDN BRI is normally deployed at remote sites and an ISDN PRI interface as the destination for terminating devices. Multiple B Channels can be bonded together but the overall bandwidth is low and the latency high.

DSL

8el’s fully managed private DSL service offers cost effective and secure connectivity between small office home office (SOHO) and an organisations head office. Advances in DSL technology have seen bandwidths increase with up to 20Mb download and 1Mb upload. Whilst DSL remains a best effort technology it is ideally suited for small user sites with short bursty data flows.

Concurrent VoIP calls over the WAN should be no more than 6. 8el’s private DSL service removes the requirement to use VPN’s to tunnel through the un-trusted Internet where no service guarantees or quality of service measures can be applied. The DSL variants available through 8el are:

• ADSL
• ADSL MAX
• ADSL 2+
• SDSL

TDM

TDM based circuits provide sufficient bandwidth for medium sized offices and offer the reliable transmission of converged voice, video and data. The bandwidth used on the TDM network is guaranteed and use is exclusive to the end user. E1 circuits played an integral part to the 8el ATM core providing the Layer1 circuit in which the Layer2 protocol ATM carried traditional voice and user data. The emergence of VoIP and the conception of 8el’s MPLS core has seen a transition from ATM to HDLC as a Layer2 protocol, removing the heavy cell tax and ATM overheads.

EFM Technology

EFM (Ethernet in the First Mile) is a synchronous, low latency technology delivered over the last mile between customer premises and network operator POP over bonded copper pairs. EFM has the ability to carry higher bandwidth connections of up to 20Mbps (dependent on provider). The service is delivered by bundling up to 8 copper pairs from the exchange to the premises to obtain the desired bandwidth throughput with the benefit of improved performance, monitoring and a better standard of QoS. Furthermore, if any of these pairs fail, the service adjusts the rate to a lower speed based on the pairs that are still running – avoiding a failure of the line as a whole.

EFM is being adopted by many wholesale network suppliers. 8el currently provides EFM circuits through BT 21CN and the TalkTalk network. EFM circuits are bound by a strict SLA along with Fiber access circuits. Sub 20ms round trip delay and sub 5ms latency. Standard repair time for EFM circuits is up to 7 hours. The synchronous nature of EFM and the low round trip delay and latency figures provide EFM with a comparable SLA to leased lines and LES circuits delivered over fiber making EFM an ideal candidate for real time traffic.

Ethernet

LAN Extension Service (LES) is a key part of 8el's WAN network solution. LES connectivity offers superior performance and is cost effective and easier to deploy and manage compared to other WAN technologies. 8el offers a flexible choice of capacity on a single circuit from a 10Mbps bearer with a Committed Data Rate (CDR) or 2Mbps to 1000Mbps. LES enables 8el to implement fast, powerful converged networks that support voice, data and video applications. LES is the ideal access method for VoIP as the IP stays as IP (with no conversion) throughout the network.

Dark Fibre

Typically used for interconnecting data centres, dark fibre is fibre optic cable where the framing is determined by the enterprise and not the service provider. Bandwidth is driven by the interfaces and CPE is connected at each end of the fibre. Dark fibre is typically installed where very high bandwidth requirements exist. 1Gb or 10Gb is the typical bandwidth provisioned across the fibre, however the use of technologies like CWDM and DWDM increase this bandwidth up to 320Gb.