Reliability of call quality is dependant on the method of connection to the Networks. X-on can incorporate Broadband and Ethernet connectivity.

Broadband Products

Broadband uses Asymmetric Digital Subscriber Line (ADSL) or Symmetric Digital Subscriber Line (ADSL) to connect to X-on via the Internet. With ADSL, the upstream data rate (to the service provider) is lower, hence an asymmetric service. With the Symmetric Digital Subscriber Line (SDSL) service, the upstream and downstream data rates are equal, and as such a better quality connection.

However, both these technologies are subject to ‘contention’, a sharing arrangement, where other data traffic at the exchange, or on the Internet, can reduce call quality or data transfer.

Broadband offers useful cost savings over ISDN, but carries a small risk to call quality and user experience. A client using Broadband needs to appreciate those risks.

The only product we recommend is called Annex M which is an SDSL connection over standard copper wires (2 pairs). This provides 1.6MB of guaranteed symmetric bandwidth.

Ethernet Products

Ethernet products include a dedicated connection to the X-on network without passing over the Internet at any stage. The risk to quality degradation is zero as no contention is involved. The bandwidth allocated to voice and data is segregated at the router.

Delivery is either over pairs of copper wires or fibre.


The copper connection is known as EFM (Ethernet First Mile), also referred to as ‘unbundled’ technology as ownership of this part of the network is removed from BT.

EFM is available in a fairly high proportion of exchanges, but not all, and so a postcode check needs to be performed.

EFM is available in 2-pair or 4-pair flavours, altering the minimum and indicative (typical) bandwidth available.

EFM typically has a minimum bandwidth of 3 or 4MB/S. Distance from exchange determines whether this is on a 2 Pair or 4 Pair connection. This is enough for at least one E1/ISDN30 which is equivalent to 2MB/S with non-compressed VoIP. This is usually sufficient for voice-only traffic, and will usually meet requirements as an ISDN replacement, exceeding the requirements of a small analogue system replacement.


Fibre is available for more demanding requirements, or where EFM is not available. Available in bandwidth chunks of 10MB/S up to 100MB/S over a ‘bearer’ (fibre) with 100MB/S capacity.

Costs are dependent on distance from exchange.

X-on offers fibre where the client requires voice AND data connectivity or where EFM is not available.

Voice Compression

X-on uses compression systems in accordance with bandwidth requirements.


Replacement Solution

X-on Cloud Telecoms provide a complete replacement for existing telephony systems, with improved reliabilty, enhanced features and at a lower cost. Along with connectivity the X-on range of Telephony products can provide a complete one-stop single bill communications solution.

For further information on Dedicated Connectivity please call Sales on 0333 332 0000.