The complete state transition table follows. States are indicated horizontally, and events are read vertically. State transitions and actions are represented in the form action/new-state. Multiple actions are separated by commas, and may continue on succeeding lines as space requires; multiple actions may be implemented in any convenient order. The state may be followed by a letter, which indicates an explanatory footnote. The dash ('-') indicates an illegal transition.
| State | 0 1 2 3 4 5 Events| Initial Starting Closed Stopped Closing Stopping ------+----------------------------------------------------------- Up | 2 irc,scr/6 - - - - Down | - - 0 tls/1 0 1 Open | tls/1 1 irc,scr/6 3r 5r 5r Close| 0 tlf/0 2 2 4 4 | TO+ | - - - - str/4 str/5 TO- | - - - - tlf/2 tlf/3 | RCR+ | - - sta/2 irc,scr,sca/8 4 5 RCR- | - - sta/2 irc,scr,scn/6 4 5 RCA | - - sta/2 sta/3 4 5 RCN | - - sta/2 sta/3 4 5 | RTR | - - sta/2 sta/3 sta/4 sta/5 RTA | - - 2 3 tlf/2 tlf/3 | RUC | - - scj/2 scj/3 scj/4 scj/5 RXJ+ | - - 2 3 4 5 RXJ- | - - tlf/2 tlf/3 tlf/2 tlf/3 | RXR | - - 2 3 4 5 | State | 6 7 8 9 Events| Req-Sent Ack-Rcvd Ack-Sent Opened ------+----------------------------------------- Up | - - - - Down | 1 1 1 tld/1 Open | 6 7 8 9r Close|irc,str/4 irc,str/4 irc,str/4 tld,irc,str/4 | TO+ | scr/6 scr/6 scr/8 - TO- | tlf/3p tlf/3p tlf/3p - | RCR+ | sca/8 sca,tlu/9 sca/8 tld,scr,sca/8 RCR- | scn/6 scn/7 scn/6 tld,scr,scn/6 RCA | irc/7 scr/6x irc,tlu/9 tld,scr/6x RCN |irc,scr/6 scr/6x irc,scr/8 tld,scr/6x | RTR | sta/6 sta/6 sta/6 tld,zrc,sta/5 RTA | 6 6 8 tld,scr/6 | RUC | scj/6 scj/7 scj/8 scj/9 RXJ+ | 6 6 8 9 RXJ- | tlf/3 tlf/3 tlf/3 tld,irc,str/5 | RXR | 6 7 8 ser/9
The states in which the Restart timer is running are identifiable by the presence of TO events. Only the Send-Configure-Request, Send- Terminate-Request and Zero-Restart-Count actions start or re-start the Restart timer. The Restart timer is stopped when transitioning from any state where the timer is running to a state where the timer is not running.
The events and actions are defined according to a message passing architecture, rather than a signalling architecture. If an action is desired to control specific signals (such as DTR), additional actions are likely to be required.
[p] Passive option; see Stopped state discussion.
[r] Restart option; see Open event discussion.
[x] Crossed connection; see RCA event discussion.