In SV, we use mailbox to get data from different modules and compare the result.
class Scoreboard;mailbox drvr2sb;mailbox rcvr2sb;
function new(mailbox drvr2sb,mailbox rcvr2sb);  this.drvr2sb = drvr2sb;  this.rcvr2sb = rcvr2sb;endfunction:new
task start();  packet pkt_rcv,pkt_exp;  forever  begin    rcvr2sb.get(pkt_rcv);    $display(" %0d : Scorebooard : Scoreboard received a packet from receiver ",$time);    drvr2sb.get(pkt_exp);    if(pkt_rcv.compare(pkt_exp))     $display(" %0d : Scoreboardd :Packet Matched ",$time);    else      $root.error++;  endendtask : startendclass
In VMM, we use channels to connect all the modules and compare the result.
class Scoreboard extends vmm_xactor;   Packet_channel   drvr2sb_chan;   Packet_channel   rcvr2sb_chan;
function new(string inst = "class",             int unsigned stream_id = -1,             Packet_channel   drvr2sb_chan = null,             Packet_channel   rcvr2sb_chan = null);      super.new("sb",inst,stream_id);          if(drvr2sb_chan == null)           `vmm_fatal(this.log,"drvr2sb_channel is not constructed");      else           this.drvr2sb_chan = drvr2sb_chan;            if(rcvr2sb_chan == null)           `vmm_fatal(this.log,"rcvr2sb_channel is not constructed");      else           this.rcvr2sb_chan = rcvr2sb_chan;          `vmm_note(log,"Scoreboard created ");endfunction:new
task main();  Packet pkt_rcv,pkt_exp;  string msg;  super.main();   forever  begin    rcvr2sb_chan.get(pkt_rcv);    $display(" %0d : Scoreboard : Scoreboard received a packet from receiver ",$time);    drvr2sb_chan.get(pkt_exp);    if(pkt_rcv.compare(pkt_exp,msg))     $display(" %0d : Scoreboard :Packet Matched ",$time);    else    `vmm_error(this.log,$psprintf(" Packet MissMatched n %s ",msg));  endendtask : mainendclass   _{Your Comment}