PDF of this tutorialEvery networking environment is unique, but there are common denominators. Enterprises and carriers share a need for high degrees of protocol support, scalability, reliability, openness, ease of installation and management, management functionality, and system efficiency in their optical-networking platforms.
Protocol Support
Systems should support all data-centric application traffic ranging up to 2,488 Mbps, including ATM, coupling link, ESCON, Ethernet, Fast Ethernet, FDDI, fibre channel, FICON, Gigabit Ethernet, SONET, SRDF, sysplex timer, T3/E3, and others.
Scalability
The optical-networking solutions that have been developed from the ground up for metro enterprise transport support pay-as-you-grow expansion. The solutions enable customers to run only a few or up to 32 channels of native-speed traffic and evolve their network topologies—point-to-point, star, rings—with the same platform. Furthermore, in-service traffic is not interrupted by the installation of additional hardware or software upgrades (including reboots). Additional channels can be added, and capacity can be extended at each network node via add-and-drop capabilities.
Reliability
Enterprises and carriers demand pure line protection for point-to-point links, as well as full path protection for ring structures. In either case, service restoration of less than 50 milliseconds is of paramount importance; otherwise, the performance of time-critical applications such as voice over Internet protocol (VoIP) could be jeopardized.
Additionally, all system components must be redundant with multiple fail-over scenarios. Enterprises and carriers frequently seek optical platforms with redundant power supplies and hot-standby functionality, for example.
Openness
Standards compliance can be a make-or-break factor in buying decisions in any area of networking.
Support for these three key network-management protocols ensures that the optical-networking platform can be easily integrated with most existing enterprise and carrier infrastructures:
- signaling network management protocol (SNMP)—the simple network management language most widely used by enterprises and emerging carriers
- TL–1—the interface used in most North American incumbent carrier environments
- Q3—a protocol used extensively in Europe and gaining prominence globally
Enterprises and carriers choosing an optical platform are also interested in standards regarding single-mode fiber (ITU–T G.652, G.653, G.654, and G.655), electromagnetic compatibility (EN 55022 class B, EN 61000–4–2 electrostatic discharge immunity tests; EN 61000–4–4 electrical fast transient/burst immunity test; EN 61000–4–6/ENV 50141 immunity to conducted disturbances, induced by radio frequency fields; EN 61000–4–8 power frequency magnetic field immunity test; EN 61000–4–3/ENV 50140; ENV 50204/EN 50082–2 and 47CFR part 15 subpart B FCC class A, VCCI Class B), mechanical and electrical safety (IEC 950, EN 60950, and UL 1950), optical safety (IEC 825–1, 2, and EN 825–1, 2), and Y2K compliance (BSI PD2000–1).
Ease of Installation and Management
Because they rely on the network-management protocols so prevalent in both enterprise and carrier environments SNMP, TL–1, and Q3, today’s leading optical platforms are user-friendly. Network administrators can become well versed on using the systems with no more than a week of training.
Some vendors’ products support plug-and-play installation, of particular benefit to enterprises and carriers whose network support staffs are strapped for time. Other platforms, originally intended for carrier deployment, require complex software configuration during installation.
Management Functionality
Enterprises and carriers require sophisticated management functionality such as configuration management, service provision and activation, service testing, and fault monitoring. In the area of system monitoring, for example, some carriers require specially designed multi-clocks and fixed clocks that can be remotely controlled, enabling the network operators to provide distinguished tariff speed for each customer and service according to service value (rather than flat rate). The carriers must be able to monitor, control, or even configure bit rates via the management system.
System Efficiency
System size is no small concern, and—as with ease of installation—it varies greatly among the various vendors’ platforms. Many of the products available with enterprise listed among their target applications were initially designed for carrier deployment and, accordingly, are too big. Some require separate refrigeration units. Enterprises and carriers want platforms that fit standard 19-inch networking cabinets. A full-loaded chassis should not exceed 25 kilograms or 150 watts in power consumption.
