Code,Summary,Description,Reference
200,OK,request has succeeded.,[RFC6505]
400,Syntax error,request is syntactically invalid: it is not valid with respect to the XML schema specified in Section 5 or it violates a co-occurrence constraint for a request element defined in Section 4.,[RFC6505]
405,Conference already exists,request uses an identifier to create a new conference (Section 4.2.1.1) that is already used by another conference on the MS.,[RFC6505]
406,Conference does not exist,request uses an identifier for a conference that does not exist on the MS.,[RFC6505]
407,Incompatible stream configuration,"request specifies a media stream configuration that is in conflict with itself, the connection, or conference capabilities (see Section 4.2.2.2).",[RFC6505]
408,Joining entities already joined,request attempts to create a join mixer (Section 4.2.2.2) where the entities are already joined.,[RFC6505]
409,Joining entities not joined,request attempts to manipulate a join  mixer where the entities are not joined.,[RFC6505]
410,Unable to join - conference full,request attempts to join a participant to a conference (Section 4.2.2.2) but the conference is already full.,[RFC6505]
411,Unable to perform join mixer operation,"request attempts to create, modify, or delete a join between entities but fails.",[RFC6505]
412,Connection does not exist,request uses an identifier for a connection that does not exist on the MS.,[RFC6505]
419,Other execution error,requested operation cannot be executed  by the MS.,[RFC6505]
420,Conference reservation failed,request to create a new conference (Section 4.2.1.1) failed due to unsupported reservation of talkers listeners.,[RFC6505]
421,Unable to configure audio mix,request to create or modify a conference failed due to unsupported audio mix.,[RFC6505]
422,Unsupported media stream configuration,request contains one or more <stream> elements (Section 4.2.2.5) whose configuration is not supported by  the MS.,[RFC6505]
423,Unable to configure video layouts,request to create or modify a conference failed due to unsupported video layout configuration.,[RFC6505]
424,Unable to configure video switch,request to create or modify a conference failed due to unsupported video switch configuration.,[RFC6505]
425,Unable to configure codecs,request to create or modify a conference failed due to unsupported codec.,[RFC6505]
426,Unable to join - mixing connections not supported,request to join  connection entities (Section 4.2.2.2) failed due to lack of support for mixing connections.,[RFC6505]
427,Unable to join - mixing conferences not supported,request to join conference entities (Section 4.2.2.2) failed due to lack of support for mixing conferences.,[RFC6505]
428,Unsupported foreign namespace attribute or element,the request contains attributes or  elements from another namespace that the MS does not support.,[RFC6505]
435,Other unsupported capability,request requires another capability not supported by the MS.,[RFC6505]