Parameter Name,Predefined Values,Reference
aai,No,[RFC5552]
bnc,No,[RFC6140]
cause,Yes,[RFC4458][RFC8119]
ccxml,No,[RFC5552]
comp,Yes,[RFC3486]
content-type,No,[RFC4240]
delay,No,[RFC4240]
duration,No,[RFC4240]
extension,No,[RFC4240]
gr,No,[RFC5627]
iotl,Yes,[RFC7549]
locale,No,[RFC4240]
lr,No,[RFC3261]
m,Yes,[RFC6910]
maddr,No,[RFC3261]
maxage,No,[RFC5552]
maxstale,No,[RFC5552]
method,"""get"" / ""post""",[RFC5552]
method,Yes,[RFC3261]
ob,No,[RFC5626]
param[n],No,[RFC4240]
play,No,[RFC4240]
pn-param,No,[RFC8599]
pn-prid,No,[RFC8599]
pn-provider,No,[RFC8599]
pn-purr,No,[RFC8599]
postbody,No,[RFC5552]
repeat,No,[RFC4240]
sg,No,[RFC6140]
sigcomp-id,No,[RFC5049]
target,No,[RFC4458]
transport,Yes,[RFC3261][RFC7118]
ttl,No,[RFC3261]
user,Yes,[RFC3261][RFC4967]
voicexml,No,[RFC4240]