Leading Edge Networking Solutions

Transceivers FAQ

1. What is the difference between SVI SFP and Original Vendor SFP?

In reality. there is no difference, Original vendor SFP are much higher in cost as they claim to be of much better quality . Most if not all, network equipment vendors do not produce their own SFP modules. These productions are outsourced to contract manufacturer and then labeled as their specific brand

2. ls it true that key equipment vendors, such as Cisco and Alcatel, only allow their SFP ports to be used by their in—house modules?

No, vendors are supposed to allow third party SFP to be used on their equipment as the SFP transceiver is specified by a multi—source agreement (MSA) between competing vendors. MSA specifies the physical dimensions, connectors, and signaling used in the SFP module so that multiple vendors can build compatible products at competitive costs.

All SVI SFP are produced with high precision in conjunction to the MSA and are compatible to use on equipments specified as a SFP port.

3. How do we define a good quality SFP?

It is a misconception that SFP depends only on optical budget. Stability and reliability is an important aspect. The performance of the optical specifications changes with temperature and aging due to time. During production. it is possible for manufacturers to increase the optical budget by purposely adjusting the optical transmit power during the calibration process. This cause the TOSA to over—perform and will have a significant impact on the stated SFP lifespan.

Our factory produces all individual components required in the SFP modules, including the TOSA and ROSA. Every stage of the SFP assembly undergoes strict quality assurance policy with uncompromising standards. Design considerations of each SFP modules are done by experienced R&D engineers in this field. We are able to provide full detailed test reports, for each product part number, with optical budget measurement. digital eye diagrams, MTBF and thermal chamber test.

4. Why some third—party SFP "refuse" to work on the equipment when the original SFP from the same equipment vendors work fine?

SFP enjoys such a huge popularity success in the industry that certain equipment vendors attempt to prevent their customers from making choices. The firmware in the equipment will check for an identifying data in the SFP‘s memory, and if the data does not belong to the equipment vendor, the equipment refuses to enable that slot. Most vendor explanation for this “feature” is that it represents a symbol of product quality and ensures that the transceiver module is certified and tested by the original vendors.

The original idea of having “ID” in the SFF—8472 was actually meant for network management software to ‘inventory the pluggable modules. However some vendors used this to lock out all other third party. This allows vendor to monopolize the transceivers for their equipment and charge at premium prices for "better" quality products.

5. Why Starview International can offer Starview International SFPs at much lower cost than the original hardware vendors?
In reality, most if not all network equipment vendors do not produce their own SFP modules. The productions are outsource to contract vendors and labeled as their specific brand. Hence, these SFP are higher in cost because of additional margins at each party.

6. How do I choose a SFP for my application?
Basic key considerations when selecting an SFP are as followings:
- Protocol/data rate used on the equipment
- Optical transmitting wavelength preference
- Optical transmission distance. Note; 60km and above, we recommend user to specify the optical budget required for the link instead.
- Type of fiber used: Singlemode /Multimode, Dual Fiber/Single Fiber
- Form Factor: GBIC, SFP, SFP+,XFP, etc
- DDM preference

7. What is Digital Diagnostic Monitoring (DDM) feature?
DDM is also known as digital optical monitoring (DOM) or Digital Monitoring Interface (DMI). Modern optical SFP support DDM functions according to the industry~standard SFF-8472. The SFP MSA defines a memory map describing the transceivers capabilities, standard interfaces. vendor. and other information. This feature gives the end user the ability to monitor real—time parameters of the SFF’. such as optical output power. optical input power. temperature. laser bias current. and transceiver supply voltage.

8. Is a SFP module hot swappable?
Yes. Starview International SFP is hot swappable. However, the equipment SFP port must be specified as hot~swappabIe as well. Please note that some equipment such as Cisco takes some time enable the physical port after inserting a new module. Also, when the physical module is removed the equipment may enter a error disable state for a configurable period of time ranging from 3Osec to 24 hours. During the error disable period. even when the fault is recovered, the data link cannot be established. The results are the same even if you use the original vendor version of SFP.