RS-449
| Application layer | HTTP, SMTP, FTP, SSH, IRC, SNMP, SIP, RTP, ... |
| Transport layer | TCP, UDP, SCTP, DCCP, ... |
| Network layer | IPv4, IPv6, ICMP, ARP, ... |
| Data link layer | Ethernet, Wi-Fi, Token ring, FDDI, ... |
| Physical layer | RS-232, RS-449, ... |
The RS449 interface is a generic connector specification. It's not an actual interface. The connector pinning was originally designed to support RS422 for balanced signals, and RS423 for the unbalanced signals. And should have been the succesor of RS232