Oracle SBC: SIP Register - Contact got modified

@10

Does anyone know why the SBC added a token or an extra value in Contact field of SIP Register message? How to disable that?

DC3-SBC-01# show version

Acme Packet 4600 SCZ8.0.0 Patch 1 (Build 121)

Oracle Linux branches-7/el7-u4 {2017-08-24T07:00:00+0000}

Build Date=11/27/17

Mar 9 18:30:11.417 [SIPREG] (2) SD-Contact: <sip:E26E50EC-7445-4BDB-BAE0-3B4BD999E5C8-44e2emrcphabd@10.220.82.85:5060> realm=MO_AIR_IN

--- REGISTER (1) --- > SBC: MO_AIR_OUT realm/sip-interface (registration-caching enabled) ----- > SBC: MO_AIR_IN realm/sip-interace (registration-caching disabled) --- REGISTER (2) --- > 10.220.82.11 (Accuroam)

When the SBC received the Register message #1, the contact field did not contain "44e2emrcphabd". However, the SBC modified the contact field and sent Register message #2 with