The common idea when changing modules is to insert whichever gear you have on hand first, but there are clear boundaries for cross-rate substitution. EB-LINK organizes the optical modules and network card grades in the station into a comparison table. The judgment sequence is to first confirm the port capability, then check the module speed, and finally check the negotiation results.
Port capabilities determine the upper limit of replacement
The SFP port is sized to accept SFP+ modules, but electrical and optical signals travel at the port design rate. It is a common practice for the 10G port to be backward compatible with Gigabit and 100M. Conversely, if the 10G or 2.5G module is inserted into the Gigabit SFP port, most models will not establish a link. The decision depends on checking the rate support list of the switch port, rather than whether the module can be physically inserted.
Determination of common alternative combinations
| want to replace | general conclusion | premise |
|---|---|---|
| Gigabit module uses 10G port | Most feasible | The port supports speed reduction negotiation |
| Gigabit port for 10G module | Not feasible | Need to be replaced with a port that supports SFP+ |
| Gigabit port for 2.5G module | Look at the model | Port declaration supports 2.5G |
| 2.5G module downgraded to gigabit | Most feasible | Actual bandwidth does not exceed Gigabit |
| 100M module replaces Gigabit link | Not recommended | The entire link will drop to 100 Mbit/s |
The gears in the table all correspond to the site specifications, such asSFP Gigabit single mode dual fiber 10KM optical module and SFP+ 10G single-mode dual-fiber 10km optical module, please also confirm that the wavelength is consistent with the fiber type before substitution.
Don't forget the chip and slot on the network card side
It is not enough for the module and the network card to have the same speed. If the number of PCIe channels is insufficient, the bandwidth will be insufficient. For dual-port models, you need to confirm how to configure aggregation. toPCI-EX8 25G dual optical port fiber optic network card (Intel XXV710 chip)For example, a 25G port and a 25G high-speed cable are of the same grade. Temporarily inserting a 10G module is only for emergency use and is not suitable for long-term storage traffic.
One-sentence notation: The port can slow down, the module cannot speed up, and the wavelength and distance are calculated separately. Checking the boxes for each of the three items before proceeding saves a round of rework compared to guessing based on model impressions, and it is also easier to leave reviewable replacement records on site.