XO Communications is one of the largest Competitive Local Exchange Carrier (CLEC) in the country. XO provides voice, data and IP services to businesses and other telecommunications companies in 75 metropolitan markets across the United States. XO Communications offers businesses advanced IP and networking solutions to maximize performance and simplify management of their networks. They also offer SIP services, hosted IP-PBX functionality (the XO One iPBX 50 powered by Avaya IP Office), VoIP origination/termination, SIP trunking, and more.

One of their flagship products, the XO IP VPN is a network-based Wide Area Network (WAN) solution delivered over the XO nationwide IP network. It's a solution aptly suited to businesses with multiple sites. The IP VPN is an advanced network allowing for faster application deployment, lower network operating costs, robust Class of Service (CoS) capabilities, and more access options than traditional WAN services.

Further, the data is segregated from other customers and the public internet. Importantly, XO offers competitive Service Level Agreements (SLAs) on packet loss and jitter.XO provides secure communications for multi-site networks, delivered over the XO private, MPLS-enabled IP backbone.

I find it interesting that XO uses IP MPLS services rather than Ethernet VPLS services. IP MPLS uses multiprotocol label switching (MPLS) over a public or private Internet connection. The advantage is that it an support any-to-any connectivity with CoS/QoS. MPLS's class of service (CoS) tagging and prioritization of network traffic, makes it easy to specify which applications should have priority. Packet classification makes an MPLS network especially important to customers that need to ensure the performance of low-latency applications such as VoIP. Additionally, MPLS carriers can offer tiered prices for each CoS tier. The disadvantage of MPLS is that it's a costly transition and complex operation.

Ethernet VPLS services on the other hand use virtual private LAN service (VPLS) over a carrier Ethernet network to provide a WAN that is configured like a LAN. The advantage is that it's simple, supports any-to-any connectivity with CoS/QoS and has lower total cost of ownership (TCO) than MPLS. But if XO built out their IP MPLS infrastructure already, it probably doesn't make sense to switch to Ethernet VPLS.

In any event, XO utilizes a nationwide OC-192 Tier 1 network along with a sizable fiber optic network, including an 18,000 route-mile inter-city network and more than 9,000 route-miles within 40 major metropolitan markets. XO claims they carry more than 15 billion minutes of VoIP traffic across its network each year.

The XO MPLS IP VPN service is a network-based Wide Area Network (WAN) solution delivered over the XO nationwide IP network. The IP VPN offers multi-site businesses more bandwidth for the dollar, faster application deployment, lower network operating costs, robust Class of Service.

Finally, XO has an IP VPN channel on TMCnet worth checking out with some good resources on IP VPNs. It includes a link for signing up for an IP VPN newsletter, news on various IP VPN industry happenings, IP VPN whitepapers, webcasts, and customer profiles. Go check it out.