cableciscolayer1routerrouting
I am doing some CCNA training videos and using packet tracer and they showed using a serial cable to connect two routers. Why are serial cables used instead of Ethernet cables? Does it depend on the router or is it just a Cisco thing?
The cable connection in question is dce to dte.
My suggestion would be to wire the socket as a single connection and then if you later decide to use it as two cables, just use a splitter (a little piece of cable with one plug and two sockets) at both ends. Just make sure to get a splitter for Ethernet (which connects two pairs to one socket and two to another) and not ISDN (which just connects both sockets in parallel).
Connecting the wires to two sockets in parallel may cause signal problems for the gigabit connection and you (or someone else) will forget to use it correctly at least once and plug one end of the cable as a single connection while connecting two computers at the other end.
Upd.
Internal wiring of ethernet splitter
Splitter kind 1, kind 2 useful for patchpanel
The answer to your question depends completely on the technology used. The complete answer to your question is far too broad, covering many different technologies, to answer here. Any distance will add to latency which can affect perceived speed, depending on the upper layer protocol used.
Fiber (there are multiple standards with various fiber types and bandwidths) will either work at the bandwidths for the standard used, or it won't work.
Some copper based technologies will either work (up to the distance limitation), or they will not work. Some (DSL comes to mind) will degrade to lower bandwidth because some of the frequency channels will not work over a certain distance while others still do.
Best Answer
One of the jobs of a router is to connect networks that have physically different transmission media. Twisted-pair Ethernet is extremely common these days, but fiber (Ethernet, SONET/OC, and others) is used for most high-speed or long-distance runs, and different types of layer-2 and layer-1 networks have been used in the past and are still in use today, such as T1/T3 lines, ISDN, and Token Ring.
For historical reasons, serial cables such as HSSI may be used to connect equipment such as T1/T3 terminating devices. These will show up as
interface SerialN, and you can get detailed information on the hardware installed in a router withshow controllers serial.Unfortunately, "DCE/DTE" technically applies to a number of different hardware signaling schemes. In the context of networking, it's most likely to refer to a serial interface that's used to connect to a WAN drop.
In the case of your simulator, you should practice with both types of interfaces. In most business networks, the "inside" interfaces will be Ethernet, while the WAN interface will be either serial or Ethernet depending on what service the telco is providing, and you'll need to be able to configure either one.