Value,Message Description,Reference
0,Reserved,
1,Call/Session disconnected due to loss of carrier,
2,"Call/Session disconnected for the reason indicated
in error code",
3,Call/Session disconnected for administrative reasons,
4,"Call/Session failed due to lack of appropriate facilities
being available (temporary condition)",
5,"Call/Session failed due to lack of appropriate facilities being
available (permanent condition)",
6,Invalid destination,
7,Call failed due to no carrier detected,
8,Call failed due to detection of a busy signal,
9,Call failed due to lack of a dial tone,
10,Call was not established within time allotted by LAC,
11,"Call was connected but no appropriate framing was
detected",
12,Disconnecting call due to mismatching SDS value,[RFC3308]
13,Session not established due to losing tie breaker (L2TPv3),[RFC3931]
14,Session not established due to unsupported PW type (L2TPv3),[RFC3931]
15,"Session not established, sequencing required without valid     
L2-Specific Sublayer (L2TPv3).",[RFC3931]
16,Finite state machine error or timeout.,[RFC3931]
17,FR PVC was deleted permanently (no longer provisioned),[RFC4591]
18,FR PVC has been INACTIVE for an extended period of time,[RFC4591]
19,Mismatched FR Header Length,[RFC4591]
20,HDLC Link was deleted permanently (no longer provisioned),[RFC4349]
21,HDLC Link has been INACTIVE for an extended period of time,[RFC4349]
22,"Session not established due to other LCCE can not support      
the OAM Cell Emulation",[RFC4454]
23,Mismatching interface MTU,[RFC4667]
24,Attempt to connect to non-existent forwarder,[RFC4667]
25,Attempt to connect to unauthorized forwarder,[RFC4667]
26,Loop Detected,[draft-ietf-l2tpext-tunnel-switching-06]
27,Attachment Circuit bound to different PE,[RFC6074]
28,"Attachment Circuit bound to different remote Attachment        
Circuit",[RFC6074]
29,Unassigned,
30,"Return code to indicate connection was refused because of      
TDM PW parameters. The error code indicates the problem.",[RFC5611]
31,Sequencing not supported,[RFC6073]