The commands?
router>en
router#conf t
router(config)#line vty 0 4
router(config-line)#password bla
router(config-line)#login
router(config-line)#end
router#wr
NOT SAFE!!! All usernames and passwords are sent over in clear text---someone sniffing the line can EASILY extract passwords!
router(config)#ip domain name local
router(config)#crypto key gen rsa
(pick 1024 for ssh ver1, 2048 for ssh ver 2, 1.99 according to Cisco)
router(config)#username bla priv 15 secret blabla
router(config)#enable secret blablabla
router(config)#line vty 0 4
router(config-line)#trans in ssh
router(config-line)#end
router#wr
This is for ssh. You can use Windows command line, any router that has k9 in the IOS code, or PuTTy (what I use).
The safest way, instead of ssh, is to make a remote access vpn, and that can be done if your router has k9 in the IOS image, which is needed for ssh anyway.
NOW---telnet is tcp port 23, used to remote console into devices, or to test connectivity on all 7 layers of the OSI model, particularly layer 4 (telnetting to a specific port indicates that port being open).
Like Forest Gump, that's all I have to say about that.
Burt