15

The distance of the fibre isn't a good indication of whether you'll be able to run a specific optic/speed across it. You need the path loss (measured in dB), which can vary greatly between links of the same distance (due to number of splices, fibre quality etc.) Also, the distance of the fibre in the ground is usually about 25-30% longer than the path it ...


11

EDIT: Fixing answer now that I'm on a real laptop. Yes, OM3 is just "laser optimized" multimode, it will work with both your optic and distance. What are the limitations in terms of bandwidth/distance? Max Distance @ 1Gbit/s (per the product page): 550m This also lines up with the OM3 specification http://en.m.wikipedia.org/wiki/Multi-...


8

You are correct. SR4 works because it's four fibres. LR4 doesn't because it's four lambdas. Even if you break out each one -- good luck finding 10G-LR optics at the exact wavelengths LR4 requires, the module itself doesn't support operating at 4x10G -- the data rate on most is 40G only.


8

Your biggest risk comes from Single Mode ER (40 Km) and ZX (80 Km) optics, which can overdrive and even burn inputs without sufficient attenuation. There is no risk of burning Multi Mode optics, as long as you're connecting MM to MM.


6

1000BASE-LX is a standard the same way 1000BASE-T is. You expect any copper interfaces with 1000BASE-T to interoperate, and you should expect the same thing with fiber 1000BASE-LX interfaces.


6

as @dfex said you really need to measure the true attenuation before proceeding. There are special transceivers that have FEC and claim to achieve extended reach (for example from Menara Networks). However I would probably go with traditional amplification and with some small DWDM system.


6

Many types of fiber connections, including 1000base-LH/LX, use two strands of fiber. However the strands are actually used individually as dedicated TX and RX on each and the traffic on each strand is entirely unidirectional. So when you are connecting two such devices, you need to cross the strands at some point so that TX on one side matches up with RX ...


6

Maybe these bugs are affecting you: CSCuj74167 (Gigabyte link from WS-C2960X-48FPD-L not coming up when using GLC-SX-MM) applies to you. Fixed in software release 15.0(2)EX4. CSCul88801 (1G or 10G in uplink ports of a Catalyst 2960x stack may not come up after a reload or OIR of SFP/SFP+. 1G or 10G SFP appear as “unknown” in the output of the show int ...


6

Electrically speaking, encoding schemes are important to keep the line balanced - even if the data changes state often enough to clock and be distinguishable from a dead line, if it has an uneven number of 1's/0's the receiver develops an unbalanced offset voltage. Encoding ensures both that there are no long strings of 1's or 0's, and that the total number ...


5

from comment HPE switches with pre-16.x firmware require original or HP-compatible transceivers. A transceiver that's not HPE branded is not activated when inserted, as indicated by LED and in the device log. You don't necessarily need an original HPE module, there's a large "compatible" market with SFPs that electronically claim to be original. With 16.x ...


5

Please realize that ethernet and IP were created by different people without knowledge of what the other was doing, and are today maintained by different organizations (ethernet=IEEE, IP=IETF). When Bob Metcalfe, et al. were creating ethernet, they were not working with Vint Cerf, et al. who were creating IP. These were two completely separate efforts. When ...


4

Traditional encoding mechanisms were built to deal with certain media characteristics - specifically electrical issues on traditional copper media or high BER carriers in the various wireless domains. With modern transmission systems there has been a push to streamline these mechanisms to simplify protocol stacks and make better use of available bandwidth ...


4

The systems simply work better with the benefits brought by various encoding schemes. So your Manchester Encoding example has the benefit of ensuring frequent -- more frequent than would be the case with typical data -- voltage changes on the wires. More frequent voltage changes have the side effect, in this example, of making clock/timing work better. ...


4

Not with a 4948-10GE I'm afraid. X2 transceivers can only go up to 10GB-ZR which will get you ~80km. Edit: dfex is right on the money as well - you'll need to get the path loss from your provider before you can make an informed decision on this. 2nd edit/suggestion - if the path loss still prohibits you from off-the-shelf optics, maybe ask your provider if ...


4

There is a "service unsupported-transceiver" configuration command that you can apply (at least on some models and IOS versions) which will allow you to continue to use transceivers manufactured by other vendors. This will, however, cause a syslog message to be emitted, and if you open a TAC case, however, the service rep may ask you to use a Cisco ...


4

You don't need to be concerned with how any ISP runs their network. All that matters to you is what they hand-off. ISP A gave you MM/10G-SR; ISP B is giving you SM/10G-LR. You will need new fiber drops and new interface modules. While the existing MM fiber might carry the new signal, passing SM over MM is problematic at the best of times -- and only works ...


4

It is the standard that you look for. In this case, it is 1000BASE-SX. Both of those transceivers use that standard, so they are compatible. It is much the same as Intel and 3Com 1000BASE-T copper transceivers that you would use on a copper-wired connection; as long as the transceivers use the same standard, they should work. You can connect two switches ...


4

From Wikipedia: A typical singlemode fiber used for telecommunications has a cladding made of pure silica, with an index of 1.444 at 1500 nm, and a core of doped silica with an index around 1.4475.[48] The larger the index of refraction, the slower light travels in that medium. From this information, a simple rule of thumb is that a signal using optical ...


3

While this is true on the fiber side of the system, and SHOULD be true on the thing with the transceiver socket (SFP, typically, for current Gigabit stuff) it is evidently not always true for certain annoying manufacturers that like to lock you into their house-brand transceivers at far above the cost of standard/generic/standards-compliant transceivers. ...


3

EDIT: GigabitEthernet SFP transceivers are supported in 1/10G SFP+ Nexus 5k slots. Please see the Nexus 5k Datasheet (see Table 2) for details. Original Answer: No FastEthernet SFPs are listed in the Nexus 5k Datasheet (see Table 2); as such, you're out of luck. FastEthernet SFPs are not supported on the Nexus 5k; however, many FastEthernet switches have ...


3

Now you don't have to buy a Cisco transceiver but you can't plug any transceiver either. The transceiver firmware must include a Cisco specific tag to be recognized by the switch / router. So when ordering you must ensure the transceiver is noted Cisco compatible and check if there's more precise compatibility information.


3

In 1000base-T there is circuitry called a hybrid which make the signal bidirectional. It's not really transmitting and receiving the wrong way round on the receive and transmit pairs, it's transmitting and receiving on all the pairs, which the other standards dedicate to transmit and receive. IEEE 802.3 defines them as "1.4.220 hybrid: A circuit (...


3

Why couldn't 10-BaseT (10Mb/s) or 100-BaseT (100Mb/s) do the same? What changed, specifically to allow this? The quality of the cabling improved drastically as well as the methods for transmitting data and the receivers used to “read” the signal from the cable. These days you could retroactively modoify the 10/100BASE-T standards to use the same ...


3

You have a multi-mode transceiver, and it will not work with single-mode fiber, and it uses a different wavelength than what you are connecting to on the other end. There is no configuration to make it work, except with multi-mode fiber. Call the supplier and have them make it right. See Cisco SFP Modules for Gigabit Ethernet Applications Data Sheet:


3

If it accepts the HP branded ones, it will likely accept the Cisco tagged one as well. If the HP one is multi-rate (and almost always are), it should work at whatever speed both sides can support. (i.e. 4)


3

If using dual pair LC fiber to run 10GbE over a long distance, what's the best way to connect it to a server on one end which has a 10GBASE-T port? The best way is to get a server NIC with SFP+ slots so that you can get a 10 Gbps fiber transceiver to match your fiber.


2

Just for people looking at this answer now (close to 3 years after the original answers): today you can get QSFP+ PLR4 transceivers that support 4x10G breakout over SMF (long range). These transceivers work by using 4 transmitters on the same wavelength but on different fibers.


2

This transceiver can do both 40G-LR4 and 4x40G LR.


2

If you aren't at all concerned with interoperability with other devices, you could try to do what you want, but increasing the clock also means that the other end needs to be identically configured, and the cabling in between, which is rated, depending on category, for certain signal speeds, would need to be compatible (e.g. crosstalk), too. Also, any ...


2

Differences in manufacturing and different types of optics ( SR,LR, ZR.. Brands.. ) It is dependent on the specific optic ( varies per each unique optic ), it is specified for the type of transceiver by the manufacturer in the datasheet. It is not a dynamic value. This is usually good enough for rough measurements but can not be considered to be as good as ...


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