router with 10 Gigabit Ethernet optical interfaces (XFP transceiver). The yellow cables are single-mode duplex fiber optic connections. There are two basic types of
optical fiber used for 10 Gigabit Ethernet:
single-mode (SMF) and
multi-mode (MMF). In SMF light follows a single path through the fiber while in MMF it takes multiple paths resulting in differential mode delay (DMD). SMF is used for long-distance communication and MMF is used for distances of less than 300 m. SMF has a narrower core (8.3 μm) which requires a more precise termination and connection method. MMF has a wider core (50 or 62.5 μm). The advantage of MMF is that it can be driven by a low cost
Vertical-cavity surface-emitting laser (VCSEL) for short distances, and multi-mode connectors are cheaper and easier to terminate reliably in the field. The advantage of SMF is that it can work over longer distances. In the 802.3 standard, reference is made to FDDI-grade MMF fiber. This has a 62.5 μm core and a minimum
modal bandwidth of 160 MHz·km at 850 nm. It was originally installed in the early 1990s for
FDDI and
100BASE-FX networks. The 802.3 standard also references
ISO/IEC 11801 which specifies
optical MMF fiber types OM1, OM2, OM3 and OM4. OM1 has a 62.5 μm core while the others have a 50 μm core. At 850 nm the minimum modal bandwidth of OM1 is 200 MHz·km, of OM2 500 MHz·km, of OM3 2000 MHz·km and of OM4 4700 MHz·km. FDDI-grade cable is now obsolete and new
structured cabling installations use either OM3 or OM4 cabling. OM3 cable can carry 10 Gigabit Ethernet 300 meters using low cost 10GBASE-SR optics. OM4 can manage 400 meters. To distinguish SMF from MMF cables, SMF cables are usually yellow, while MMF cables are orange (OM1 & OM2) or aqua (OM3 & OM4). However, in fiber optics there is no uniform color for any specific optical speed or technology with the exception being the angled physical contact connector (APC), being an agreed color of green. There are also
active optical cables (AOC). These have the optical electronics already connected eliminating the connectors between the cable and the optical module. They plug into standard SFP+ sockets. They are lower cost than other optical solutions because the manufacturer can match the electronics to the required length and type of cable.
10GBASE-SR 10GBASE-SR ("short range") is a port type for
multi-mode fiber and uses 850 nm lasers. Its
Physical Coding Sublayer (PCS) is 64b/66b and is defined in IEEE 802.3 Clause 49 and its
Physical Medium Dependent (PMD) sublayer in Clause 52. It delivers serialized data at a line rate of . The range depends on the type of multi-mode fiber used. MMF has the advantage over SMF of having lower-cost connectors; its wider core requires less mechanical precision. The 10GBASE-SR transmitter is implemented with a VCSEL, which is low cost and low power. OM3 and OM4 optical cabling are sometimes described as
laser optimized because they have been designed to work with VCSELs. 10GBASE-SR delivers the lowest cost, lowest power and smallest form factor optical modules. There is a lower cost, lower power variant sometimes referred to as 10GBASE-SRL (10GBASE-SR lite). This is inter-operable with 10GBASE-SR but only has a reach of 100 meters.
10GBASE-LR 10GBASE-LR (long reach) is a port type for single-mode fiber and uses 1310 nm lasers. Its 64b/66b PCS is defined in IEEE 802.3 Clause 49 and its PMD sublayer in Clause 52. It delivers serialized data at a line rate of 10.3125 GBd. 10GBASE-LRM uses electronic dispersion compensation (EDC) for receive equalization. 10GBASE-LRM allows distances up to on FDDI-grade multi-mode fiber and the same 220m maximum reach on OM1, OM2 and OM3 fiber types. To ensure that specifications are met over FDDI-grade, OM1 and OM2 fibers, the transmitter should be coupled through a mode conditioning patch cord. No mode conditioning patch cord is required for applications over OM3 or OM4.
10GBASE-ER 10GBASE-ER (extended reach) is a port type for single-mode fiber and uses 1550 nm lasers. Its 64b/66b PCS is defined in IEEE 802.3 Clause 49 and its PMD sublayer in Clause 52. It delivers serialized data at a line rate of 10.3125 GBd.
10GBASE-ZR Several manufacturers have introduced range under the name 10GBASE-ZR. This 80 km PHY is not specified within the IEEE 802.3ae standard and manufacturers have created their own specifications based upon the 80 km PHY described in the
OC-192/
STM-64 SDH/
SONET specifications.
10GBASE-LX4 10GBASE-LX4 is a port type for multi-mode fiber and single-mode fiber. It uses four separate laser sources operating at and
Coarse wavelength-division multiplexing with four unique wavelengths around 1310 nm. Its
8b/10b PCS is defined in IEEE 802.3 Clause 48 and its
Physical Medium Dependent (PMD) sublayer in Clause 53. These advances were subsequently standardized in IEEE 802.3cp-2021 with reaches of 10, 20, or 40 km. ==Copper==