There is a complete NTP book on CDR. There are two formats - Old and New. Most systems use the old format.
Here is the old format:
N 001 00 DN4999 A000009 7.1.02.1 06/28 10:15 00:00:20 9828124
N=Record Type (n=normal, s=Start, e=End)
001=Record number
00=Customer Number
DN4999=Originating ID (in this case ext 4999)
A000009=Terminating ID (in this case Answer supervised route 000 trunk member 009)
7.1.02.1=TN of Set (only appears if mutliple apearance DN)
06/28=date Stamp
10:15=Time Stamp
00:00:20=Call Duration
9828124=Digits Dialed and or outpulsed
As far as the TTY connection, use 7 bits, 1 stop bit, even or space parity. The Baud rate will depend on either the programming or dipswitch setting depending on the system and SDI Board type used.