276 CHAPTER 17: F UNDAMENTAL CT3 I NTERFACE CONFIGURATION COMMANDSExamples # Configure T3 2/0 interface to operate in the FT3 mode, setting the DSU mode to1 and the subrate to 3000 kbps. system-view[Sysname] controller t3 2/0[Sysname-T3 2/0] using t3[Sysname-T3 2/0] ft3 dsu-mode 1[Sysname-T3 2/0] ft3 subrate 3000loopback (CT3 interface view)Syntax loopback { local | payload | remote }undo loopbackView CT3 interface viewParameter local: Enables internal loopback on the CT3 interface.payload: Enables external payload loopback on the CT3 interface.remote: Enables external loopback on the CT3 interface.Description Use the loopback command to configure the loopback mode for a CT3 interface.Use the undo loopback command to disable loopback.By default, loopback is disabled on CT3 interfaces.Loopback is intended for test use. Disable it otherwise.If a CT3 interface encapsulated with PPP is placed in a loopback, it is normal thatthe state of the link layer protocol is reported down.Example # Enable internal loopback on interface T3 2/0. system-view[Sysname] interface t3 2/0[Sysname-T3 2/0] loopback localmdl (CT3 interface view)Syntax mdl { detect | data { eic string | fic string | | gen-no string | lic string | pfi string |port-no string | unit string } | generate { idle-signal | path | test-signal } }undo mdl [detect | data [ eic | fic | gen-no | lic | pfi | port-no | unit ] | generate[idle-signal | path | test-signal ] ]View CT3 interface viewParameter detect: Enables periodical maintenance data link (MDL) message detection.
