Polycom RealPresence 1800 Administration Manual page 328

Disconnection Cause Values
Value Call Disconnection Cause
481 SIP client error 481
482 SIP client error 482
483 SIP client error 483
484 SIP client error 484
485 SIP client error 485
486 SIP busy here
487 SIP request terminated
488 SIP client error 488
500 SIP server error 500
501 SIP server error 501
502 SIP server error 502
503 SIP server error 503
504 SIP server error 504
505 SIP server error 505
600 SIP busy everywhere
603 SIP global failure 603
604 SIP global failure 604
606 SIP global failure 606
Polycom, Inc.
Disconnection Causes
307