In addition to 10 GbE, the telecom market nowadays is also actively deploying 40 GbE connections to support server connectivity, the typical use case is switch-to-switch interconnects. In fact, copper cables are used in some special cases, primarily for switch-to-switch short-reach connections. However, with the majority of 40 GbE connections being optic fiber-based, fiber optic cables, especially the MTP/MPO cables are widely deployed. From a cable plant standpoint, continued investment in fiber parallel-optic technologies will position the physical infrastructure for eventual migration to 100 GbE and beyond. This article will provide available physical cable technologies for 10G and 40G connectivity.
10 GbE Cable Solutions
Higher transmission speeds require us to implement new cable technologies to optimize our 10 GbE infrastructure:
This connection over unshielded or shielded twisted-pair cables can support distances over 100 meters (330 feet) with Category 6a cable, 55 meters with Category 6 cable, and 45 meters with Category 5e cable. Category copper cables like cat5e and cat6 cable reel are the most commonly used types. We are using limited 10GBASE-T to serve the high-density connectivity within racks. 10GBASE-T has some cost advantages but it also consumes more power than optical technology.
- Small-Form-Factor Pluggable (SFP+) direct-attach cables.
These twin-axial cables support 10 GbE connections over short distances of up to 7 meters. Some suppliers are producing a cable with a transmission capability of up to 15 meters.
Connect two Cisco Catalyst 4948E-F Switches with a 10G SFP+ Passive Direct Attach Copper Twinax Cable.
- MPO cabling.
We are using this technology to simplify cabling and reduce installation cost because it is supported over SFP+ ports. One trunk cable that we use can support 10 GbE up to 90 meters and provides six individual connections. This reduces the amount of space required to support comparable densities by 66 percent. The trunks terminate on a variety of options, providing for a flexible system.
We use an MPO cable, which is a connectorized fiber technology comprised of multi-strand trunk bundles and cassettes. This technology can support 1 GbE and 10 GbE connections and can be upgraded easily to support 40 and 100 GbE parallel-optic connections by simply swapping a cassette. The current range for 10 GbE is 300 meters on OM3 MMF and 10 kilometers on SMF.
40GbE Switch-to-Switch Interconnects
A 40 GbE switch-to-switch interconnect can use one of three methods.
- QSFP+ transceivers and MMF MPO trunks.
This configuration must use a Method B polarity MPO trunk.
- Long-range QSFP+ transceiver and standard 2-strand SMF connections.
- Active optical cable.
This is a pre-terminated parallel-optic solution which incorporates a 12-strand MMF bundle connected on each end with a QSFP+ transceiver. This type of cable is available in standard lengths up to 100 meters. This configuration is used for 40 GbE connections that span rows within the data center.
The existing 100Mbps and 1GE connections no longer support growing business requirements, so here comes the era of 10G and 40 GbE data center fabric design. The new fabric will reduce data center complexity and increase our network agility to meet growing data center needs. Today’s article offers suitable fiber optic solutions for a 10G/40G switch to switch interconnects.