Hi, Linkset??? Should be host configuration. I assume the linkset configuration is missed in your ss7.conf > > > > 3. Linkset: > > [host-gw1.enum.cdit.com.vn] > > enabled => yes > > opc => 0x11ae > > dpc => siuc:0x11a9 > > links => si:4,vo:2 > > ssn => > There should be channel configuration in zaptel.conf as well. Please take a look at my working configuration below. > > 7 > > II. in Zaptel.conf > > span=1,0,0,ccs,hdb3,crc4 > > *span=2,1,0,ccs,hdb3,crc4* > > span=3,0,0,ccs,hdb3,crc4 > > *span=4,2,0,ccs,hdb3,crc4* > > * *** > > I have a single E1 card. The C7 signaling is at channel 16 on port 1 of the card. My zaptel.conf reads: span=1,1,0,ccs,hdb3,crc4 bchan=1-31 span=2,0,0,ccs,hdb3,crc4 bchan=32-62 span=3,0,0,ccs,hdb3,crc4 bchan=63-93 span=4,0,0,ccs,hdb3,crc4 bchan=94-124 my ss7.conf reads ; linkset configuration [linkset-siuc] enable_st => yes use_connect => yes hunting_policy => even_mru context => ss7_in language => en t35 => 4000, timeout subservice => auto ; links configuration [link-L1] enabled => yes linkset => siuc channels => 1-15, 17-31 ; bchan schannel => 16 ; as mentioned above. The C7 signaling is at channel 16 / port 1 *firstcic => 1* echocancel => no echocan_train => 350 echocan_taps => 128 [link-L2] enabled => yes linkset => siuc channels => 1-31 schannel => *firstcic => 33* echocancel => no echocan_train => 350 echocan_taps => 128 [link-L3] enabled => yes linkset => siuc channels => 1-31 schannel => *firstcic => 65* echocancel => no echocan_train => 350 echocan_taps => 128 [link-L4] enabled => yes linkset => siuc channels => 1-31 schannel => *firstcic => 97* echocancel => no echocan_train => 350 echocan_taps => 128 ; host configuration [host-my.superbs.ding.dong] enabled => yes opc => <the point code provided by telco> dpc => siuc:0x1650 links => L1:1, L2:2,L3:3,L4:4