Ethernet Technology

Ethernet (IEEE standard 802.3) is a frame-based networking protocol that has been widely deployed in local area networks (LANs) for over a decade. Its prevalence in the LAN can be attributed to its operational simplicity and cost-effectiveness. More recent developments of the Ethernet standard have facilitated the expansion of Ethernet deployments from campus to commercial use, and from local to wide area networks (WANs).

One such development is the Virtual LAN (VLAN) standard (IEEE 802.1Q). VLANs allow several distinct networks to operate privately and securely over the same physical infrastructure by dedicating a VLAN ID to each virtual network. Another key breakthrough is the development of real-time failover technologies, including Rapid Spanning Tree and Ethernet Automatic Protection Switching (RFC 3619). Both provide sub-second failover to secondary paths when employed within ring network topologies.

Ethernet operates at the Data Link layer (Layer 2) of the 7-layer OSI model. Using Ethernet for the WAN in addition to the LAN environment obviates the need for conversion of data to higher layer protocols and provides some dramatic performance advantages over multi-protocol solutions. These include:

Latency — Latency is typically measured in milliseconds (ms) and is defined as the round-trip delay in data packets between locations. Low-latency is required by time-sensitive network applications. Latency increases as physical distance between locations increases. However, latency is also introduced each time data must be "processed" by a switch or router. So every time a data packet requires analysis, conversion, routing, etc., microseconds are added to the travel time of the packet. Because native, switched Ethernet is less process-intensive than routed TCP/IP, Ethernet networks offer a significant latency advantage over IP networks.

Jitter — Jitter is defined as the variation in latency and is typically measured in microseconds. Low-latency is critical to performance-sensitive network applications that require a high level of consistency. Voice over IP and real-time video applications are examples of such applications. Similar to latency, each time data must be handled by a switch or router, there is the potential for jitter to be introduced. So, all things being equal, Ethernet networks tend to outperform IP-based networks on this important metric.

Efficiency — Application data that remains at Layer 2 will not require the substantial overhead that is required for Layer 3 packet routing. When Jumbo Ethernet frames (greater than 1522 Byte MTUs) are employed with a GigE interface, the efficiency gains are even greater, allowing networks to deliver more traffic with less bandwidth.

The cost advantages of Ethernet are as compelling as the performance advantages. Transmission at Layer 2 eliminates the need for protocol conversion equipment or Layer 3 routing hardware. Reliance Globalcom provides fully-managed, end-to-end Ethernet-based services that are delivered with a standard Ethernet interface by which customers connect directly to Reliance Globalcom's global native Ethernet network. No additional switch, router, CSU/DSU, or other hardware is required of the customer.

Reliance Globalcom offers enterprises a reliable and cost-effective way to connect offices across town, across the nation, or around the world quickly and easily. Reliance Globalcom's Ethernet services are perfectly suited for the most demanding applications. Low-latency and jitter are guaranteed by aggressive Service Level Agreements (SLAs) while redundant fiber rings and diverse Internet connections ensure the highest levels of network availability and stability.