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SONET/SDH Optical Interface Cards

All current industry-standard SONET/SDH interface types are available for the ONS 15454 platform, including OC-3/STM-1, OC-12/STM-4, OC-48/STM-16, and OC-192/STM-64. These interface cards are typically distinguished by bandwidth, wavelength, and number of ports; however, with the newer interfaces based on Small Form Factor Pluggable (SFP/XFP) technology, these parameters can vary from port to port on the same interface card. Therefore, we briefly discuss the available card types in terms of two categories: fixed optics interfaces and modular optics interfaces.

Fixed optics interfaces are those for which the bandwidth (for example, OC-12/STM-4), the wavelength (for example, 1310 nm), and the number of equipped ports (for example, a four-port OC-12/STM-4 interface card) are predetermined parameters that cannot be field-modified. Table 6-4 gives a listing of these interfaces, including card name, SONET/SDH bandwidth for each port, transmitter wavelength, the number of ports included on the interface card, and the quantity and type of optical fiber connectors on the card's faceplate.

Table 6-4. ONS 15454 Fixed Optics Interfaces

Card Name

Per-Port Bandwidth (Mbps)

Wavelength (nm)

Number of Ports

Connectors

OC3 IR 4/STM1 SH 1310

155.52

1310

4

8 SC

OC3 IR/STM1 SH 1310-8

155.52

1310

8

16 LC

OC12 IR/STM4 SH 1310

622.08

1310

1

2 SC

OC12 LR/STM4 LH 1310

622.08

1310

1

2 SC

OC12 LR/STM4 LH 1550

622.08

1550

1

2 SC

OC12 IR/STM4 SH 1310-4

622.08

1310

4

8 SC

OC48 IR/STM16 SH AS 1310

2488.32

1310

1

2 SC

OC48 LR/STM16 LH AS 1550

2488.32

1550

1

2 SC

OC48 ELR/STM16 EH 100 GHz

2488.32

Various [*]

1

2 SC

OC192 SR/STM64 IO 1310

9953.28

1310

1

2 SC

OC192 IR/STM64 SH 1550

9953.28

1550

1

2 SC

OC192 LR/STM64 LH 1550

9953.28

1550

1

2 SC

OC192 LR/STM64 LH ITU 15xx.xx

9953.28

Various [1]

1

2 SC

A card name that includes the IR (and SH) designations indicates a card designed for intermediate-reach (short-haul) applications. A card with the LR/LH designations indicates a long-reach/long-haul card. Similarly, ELR/EH (extended long reach/extended haul) and SR (short reach) are indicative of the card's transmission distance specifications.

Modular optics interfaces are those for which the bandwidth, the wavelength, and possibly even the number of equipped ports are parameters that are made flexible through the use of SFPs or XFPs. SFPs and XFPs are essentially electrical-to-optical signal converters that provide a modular interface between a port on an interface card and the external fiber-optic cabling. SFPs and XFPs are similar in design; the primary difference is the module size (XFPs are larger). Modular optics are available for various wavelengths, optical reaches, and technologies, such as SONET/SDH and Gigabit Ethernet (GigE). An SFP or XFP is inserted into the required card port faceplate receptacle and provides a transmit/receive pair of LC fiber connectors. Figure 6-10 shows a group of SFPs, as well as an enlarged view of an SFP connector end.

bm740610.jpg

Figure 6-10 SFP Interface Modules

Currently, two SONET/SDH interfaces take advantage of SFP/XFP technology to offer user flexibility and maintenance spare savings:

  • OC-192/STM-64 Any Reach— This is a 10G interface card with a single XFP port capable of housing an SR, IR, or LR XFP module. Having a single card to stock (while maintaining a maintenance inventory of 10G XFPs) allows a carrier customer to realize efficiencies in maintenance sparing.
  • MRC-12— The 12-port multirate card (MRC) contains 12 modular SFP receptacles, with the various ports capable of being equipped for OC-3/STM-1, OC-12/STM-4, or OC-48/STM-16 operation. In addition to savings related to maintenance sparing, this card enables the network operator to equip ports for SONET/SDH services on demand. This flexibility also allows for a much more efficient use of chassis slots. For example, a single MRC-12 card can be equipped with one or more OC-48/STM-16 ports, one or more OC-12/STM-4 ports, and one or more OC-3/STM-1 ports, and to use only a single card slot in the chassis instead of a minimum of three slots if fixed interface card types were used. Combinations of each port type can be used, up to the maximum available slot bandwidth, which varies based on the equipped cross-connect card type.
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