when attempting to make a telnet connection to a remote router, the connection fails. you check the interface status on your local router and find the following: serial0/1/0 is up, line protocol is up hardware is gt96k serial internet address is 192.168.2.1/24 mtu 1500 bytes, bw 1544 kbit, dly 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 encapsulation hdlc, loopback not set keepalive set (10 sec)... (additional output omitted) you ping the remote router, but that fails as well. at which layer of the osi model does this problem originate?