Maximum length of a field "FROM" in the SIP?

SIP Channel
from Lync of the server I receive such type of SIP inquiry:
[] Message Header
[truncated] From: "\320\241\320…
SIP Display info: "\320\241\320…\207"
SIP from address:;user=phone
SIP from address User Part: 37050
SIP from address Host Part:
SIP from URI parameter: user=phone

When field length “SIP Display info” too long - sip connection from the Lync2013 to Asterisk dropped…
I ask:
in what file and in what place the maximum length of this field in an accepted package is specified ?