8GFC and 10GbE SFP + To replace the XFP

Chip manufacturers and supplier of optical devices are release next  optical transceiverstandards available for 8Gb / s Fibre Channel (8GFC) and possible 10Gb / s Ethernet (10GbE) , and eventually replace the XFP transceiver.

SFP + modules are smaller than XFP for clock and data recovery circuit from the chip to the line card (linecard). This allowed the module is reduced to 2.5Gb / s port SFP (small-form pluggable SFP) size.

Where is the problem? Prima facie, the things added to the line card in the works on relatively module easier. Turned to the SFP + optical module can reduce costs. Johny says, “many of our customers tell us they need to find ways to reduce connection costs, which is a way.”

Of course, the SFP + has also brought a problem, because the line card now carries more than one chip, in addition to the Ethernet physical layer chip, as well as MAC and other. Foundry Networks Bill Ryan said line card “in the back-end is still accounted for a lot of places.”

SFP + smaller size density line cards from 16 of the XFP card to at least 24. The same time, the outside of the circuit anti-theft module did not allow each module services opens the door – Gigabit Ethernet in the number of lines is to do so. Voois said, “This is really driving cost reduction.”Join the SFP + for 10Gb / s Ethernet, it will become the newest member of a series of modules thin. This industry began in 300-pin MSA (multisource agreement, Multi-Source Agreement), and then the smaller Xenpak and X2 module type, then it will be smaller XFP replace.

If the SFP + really so good, why not previously? The problem is that 10Gb / s signal through a common line cards will be distorted. Xenpak, X2 and 300-pin MSA divided by the signal to multiple parallel lines to fix, XFP retains a serial 10Gb / s stream is usually followed by the SerDes with the line card (the serializer to / deserializer and serializer / serial separation device) to split into parallel streams.In the past few years, Broadcom, Marvell Technology Group Corporation and Rambus companies, manufacturers of signal processing technology to overcome the above problems. Salem said that “a few years ago, people said you can not 10Gb / s on the PCB (printed circuit board), this is not the problem.”

SFP + name adopted with a standard SFP (Small-Form the Pluggable, small form pluggable) module of the same physical size, for the majority of 2.5Gb / s or slower port. This raises a doubt, that the SFP + standard is designed to make older SFP modules in the same slot? If the answer is yes, the equipment manufacturers were able to assembly port range from 1 Gb / s to 10Gb / s ports system.This standard in the Ethernet field of prospects worth the wait. Voois said engage Ethernet guys think it is applicable, FC camp just sort of like – ‘why bother us?’ Ethernet camp will not be disturbed in any case they will join in and disrupt the meeting. ”

Some module manufacturers to identify the samples of SFP + module, they want to make at the end of this year or early 2007. As for the system vendors, they usually take a separate view, saying that they do not worry.Foundry’s Ryan said, “We have long-term assessment of the SFP + very satisfied with our XFP density, the biggest problem is the cost of optical devices.”