For MSC encoded as one of the following according to the requirements of the Sender PMN.
   The MSISDN of the entity as per 3GPP TS 23.003 e.g. 44836100456
   The signalling point code as per 3GPP TS 23.003  e.g. 253464
   A name e.g. “HELSINKI”  Note: must be uppercase.
For SMSC entity as per 3GPP TS 32.005 (Msisdn).
For GSN entities as per 3GPP TS 32.015 (GSNAddress).
For GSN entities, where SMS usage is recorded, as per 3GPP TS
32.005 or 3GPP TS 32.015 (GSNAddress or Msisdn).
For GMLC entities as per 3GPP TS 32.205 and 3GPP TS 32.215 (Msisdn) or as Ipv4 Address or as Ipv6 Address.
For WLAN network usage this could be the name (uppercase) or an IP address of the WLAN billing information recording entity.