private bool IsExpiresValid(SipMessageReader reader)
{
int expires = reader.GetExpires(defaultExpires, maxExpires);
for (int i = 0; i < reader.Count.ContactCount; i++)
{
int localExpires = reader.Contact[i].Expires;
if (localExpires == int.MinValue)
localExpires = expires;
if (localExpires != int.MinValue && localExpires > 0 && localExpires < minExpires)
return false;
}
return true;
}