What does the "T" shape mean here?

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There is a logogram, but I want to know the RTA's left side port whether is config the network segment's IP address.

This is Quidway technology.

3 Answers 3


It represents a multi-access local network, such as ethernet. It's just drawn vertically so looks a little unusual.

It shows that the network address on the left is, but doesn't specify the address of the interface of RTA. The network on the right of RTB is, again without specifying the address of the interface of RTB.

  • 5
    In a word: "bus" (the lightning in the middle is "point-to-point")
    – Ricky
    Commented Oct 23, 2018 at 13:53
  • @RickyBeam "bus" is the cable which all computers in an Ethernet network connect to ?
    – doubleOrt
    Commented Oct 23, 2018 at 20:16
  • "bus" means shared wire or wires, with multiple connections, from "bus bar" in electrical circuits (from "omnibus", all together, ultimately from Latin omnibus, "all"). In a networking sense it means shared medium, though I've never heard it used for radio, only wired and optical. Also use analogously in software.
    – jonathanjo
    Commented Oct 24, 2018 at 8:47

It's not a letter T, it's the connecting lines to other devices on that network segment. However since there are not any other devices, that is simply the artists choice as how to represent such a segment. If there were additional devices, then you would see the lines extended to accommodate the additional devices.

Also, just because it's a plain, flat line doesn't imply anything about the underlying technology (e.g. ethernet), it's just a generic link.


That is how you represent a loopback interface, which is a virtual interface, an interface not associated with any hardware where you can assign an ip/mask. You can check over Cisco documentation, they use them a lot:

Nat on a stick two loopback interfaces

  • Welcome to network engineering! As you can see from the other answers, the symbol usually represents a network segment. For educational purposes, loopback are often configured as interfaces on a subnet, as in your diagram. In real networks, they are more often configured with a host (/32) address.
    – Ron Trunk
    Commented Oct 24, 2018 at 0:21

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