It is very important to know the type of polishing used in a facility, as it will help us to reduce light losses in the different links.
There are currently 4 types of polishing, although the most used are PC polishing (flat polishing) and APC polishing (polishing with an angle).

• FLAT or plane: It is used in multimode installations and its cut is flat. The return loss oscillates in <-30db.
• PC or Phisical contact: It was usedin single-mode and multi-mode installations. It is the most common polishing in fiber facilities.
  Its polishing is convex and it has the best properties of loss of return, between <-35db.
  Its connector is blue.
• UPC or Ultra Phisical Contact: Used for single-mode fiber installations. It is equal to the polished PC, but it does not reflect as much light as the polished PC.
  Your return loss is around <-55db. It is a polish usedin digital systems and telephony installations.
  Its connector is Blue.
• APC or Angled Physical Contact: This is an 8 degree angular polish. With a loss return of <-65db.
  Its connector is green.

LSHF Cable (Low Smoke Halogen Free Cable) or also called LSZH (Low Smoke Zero Halogen) is a type of international classification that is used to cover the wires in the cable industry both steel and other types. LSHZ has a thermoplastic coating that propagate little heat sources. Another carasterística do not emit toxic gases or fumes when exposed to flame. You have to take into account that surfacertas facilities may be required by the competent authority using these cables.

It gives transmission distance. Types fiberoptic

• Single mode (single mode): Only one mode light propagates. Allow distances up to 400 km and very high speeds. The usual size of 9/125 microns fiber is.
• Multimode (multi mode): The light is spread by more than one way. . Used for transmission at close range, no more than 2 Km Typical multimode fibers are according to ISO: OM1 (62., Data transmission is changing direction. In a duplex system, each of the fibers is used for transmission in one direction. Therefore, the duplex installations are faster and more efficient.