14.6.1.2.3. Extension in Node 10-69-100 
The HG 3500 in node 10-69-200 must be retrofitted in node 10-69-100
for LEGK (AMO GKREG). For node 10-69-100, this HG 3500 (GWNO=2)
is an external gateway (attributes EXTGW&HG3550V2&SIPQ/SIP)
and is not registered in node 10-69-100.
ADD-GKREG:GWNO=2,GWATTR=EXTGW&HG3550V2&SIPQ or SIP,GWIPAD DR=1.69.21.80,DIPLNUM=0,DPLN=0,LAUTH=1;