Over the years, we have identified some frequently asked questions from our customers. If you have a question about our products, there is a good chance that the answer to your question is here in our FAQ section.
Click on the bar below to choose between questions regarding our industrial Ethernet products or questions regarding our general products.
Q.1 What is the difference between auto-sensing and auto-negotiation functions?
Ans:
Auto-sensing - will work on either 10Mbps or 100Mpbs networks. Auto-negotiation - will work on both 10Mbps and 100Mbps, and at half or full duplex mode.
Q.2 What is the maximum point-to-point transmitting distance for a 100Base-TX/FX multi-mode fiber converter?
Ans:
By multi-mode fiber mode, the Fast Ethernet converters can extend to distances up to 2km.
Q.3 What is WDM converter?
Ans:
WDM is the acronym of Wavelength Division Multiplexing. Ordinary multi-mode or single-mode fiber converter transmits data in transmitting and receiving directions by two fibers. WDM multiplex and demultiplex two channels for both directions in one fiber by division and integration of two optical wavelengths. The wavelengths of 1310nm and 1550nm are used for WDM. The "TS" model uses 1310nm for transmitting direction and 1550nm for receiving direction. The "RS" model uses 1550nm for transmitting direction and 1310nm for receiving direction. "TS" model and "RS" model must be used in pairs at two sides of the fiber link.
Q.4 How does the Loopback Test (LBK) work?
Ans:
The LBK feature is designed to allow users to conduct self-diagnostic tests on ports and cables to see if they were properly connected during installation. LBK can also be good for troubleshooting on port or cable connections if problems occur. There are two types of loopback tests: Local Loopback and Remote Loopback. Local Loopback bounces back the received packets on copper port. Remote Loopback bounces back the received packets on fiber ports. Loopback Test offers a simpler approach to troubleshooting; no more manual inspection of cables and wiring closets.
Q.5 What is the maximum point-to-point transmitting distance for a 100Base-TX/FX single mode fiber converter?
Ans:
A converter using single-mode fiber will extend to distances of 30km, 40km, 60km, 100km, and up to 120km.
Q.6 For optimal performance, what is the best way to deploy a 100Base-TX/FX converter?
Ans:
To fully utilize the fiber's long-range transmission advantage, the 100Base-TX/FX converters should be deployed together with switches and not hubs. Switches support full duplex mode. This allows point-to-point connection of up to 2km for multi-mode fiber and up to 120km for single-mode fiber.
Q.7 Why do we need Gigabit multi-mode-SX-to-single-mode-LX converters?
Ans:
At present, a 10/100 LAN switch with a Gigabit module or Gigabit switch comes with 1000Base-SX gigabit port(s) that will only support point-to-point connections of up to 280m. A Gigabit multi-mode-SX-to-single-mode-LX converter has the potential to extend this distance to 10km.
Q.8 What is the maximum point-to-point transmitting distance for Gigabit multi-mode-SX-to-single-mode-LX converters?
Ans:
The maximum point-to-point transmitting distance is 10km + 280m = 10,280m.
Q.9 How does the Link Fault Signaling (LFS) work?
Ans:
LFS is designed to monitor the link status of converters. The LFS LED, when lit, indicates any fiber- or copper-cable failure in the network. When the LFS LED is off, this indicates that the connection is stable.
To explain how LFS works with redundant link, four converters can be used to build a primary and a secondary link. They must be connected to a switch that supports Spanning Tree or Rapid Spanning Tree Protocols. By default, transmission of data will travel via the primary link. Once a fault has been detected, transmission will automatically be switched to the secondary link, resulting in non-stop connectivity.
Step 1. Primary link is interrupted Step 2. Converter automatically triggers LFS function to shut down all ports Step 3. The switch's Spanning Tree Protocol (STP) routes transmission via the redundant link.
Q.10 What is IGMP Snooping and how does it work?
Ans:
IGMP Snooping provides a method for intelligent forwarding of multicast packets within a Layer 2 broadcast domain. By snooping IGMP registration information, a distribution list of workstations is formed that determines which end-stations will receive packets with a specific multicast address.
Layer 2 switches treat IP multicast traffic in the same way as broadcast traffic– namely, by forwarding frames received on one interface to all other interfaces. The larger the networ; the bigger the impact of this superfluous multicast traffic. In the diagrams above and below we see that, by introducing IGMP snooping on the switch, only hosts that are group receivers actually receive multicast traffic.
Q.11 How do web-browser and SNMP network-management software work in converters?
Ans:
Web-browser management software allows MIS personnel to monitor and manage network status and devices from a remote site via browser program like Microsoft Internet Explorer or Netscape Communicator. SNMP is the network management standard allowing integration of management tasks within Network Manager System. VOLKTEK products implement SNMP Agent process corresponding to management requests from Network Manager via IP network connected to any RJ-45 port and send out SNMP trap messages for alarm notification.
Q.12 What are the 1000Base-SX and 1000Base-LX, and what is their availability?
Ans:
The 1000Base-SX is a converter that can extend distances up to 500m if 50/125 microns multimode fibers were to be used, and 10km if used with 9/125 microns single-mode fiber. The 1000Base-LX is a Gigabit long-haul single-mode fiber converter that can support up to 70km if used with 9/125 microns single-mode fiber.
Q.13 What is Stacking and Cascading?
Ans:
Stacking: to connect two or more switches or hubs together by using an SCSI cable. The cable plugs into the rear port of each switch or hub. Cascading: also to connect two or more switches or hubs together, but by using UTP cables to plug into the ports located at the front of each switch or hub. Stacking is the better solution when the devices are near to each other, while cascading is more suitable for linking devices that are further apart and of differing makes.
Q.14 What are the distances for Media Converter applications?
Ans:
The following is the standard multi-mode and single-mode distance table for Media Converters.
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