config := gosnappi.NewConfig()
	port1 := config.Ports().Add().SetName("port1").SetLocation(opts.IxiaCPorts()[1])
	port2 := config.Ports().Add().SetName("port2").SetLocation(opts.IxiaCPorts()[2])

	// port 1 device 1
	devA := config.Devices().Add().SetName("devA")
	// port 1 device 1 ethernet
	devAEth := devA.Ethernets().Add().
		SetName("devAEth").
		SetMac("00:00:01:01:01:01").
		SetMtu(1500)
	devAEth.Connection().SetPortName(port1.Name())

	// port 1 device 1 ipv4
	devAIpv4 := devAEth.Ipv4Addresses().
		Add().
		SetAddress("1.1.1.2").
		SetGateway("1.1.1.1").
		SetName("p1d1Ipv4").
		SetPrefix(24)

	// port 1 device 1 isis
	IsisRouterA := p1d1.Isis().SetName("IsisRouterA")

	// port 1 device 1 isis basic
	IsisRouterA.Basic().SetIpv4TeRouterId(p1d1Ipv4.Address())
	IsisRouterA.Basic().SetHostname("ixia-c-port2")
	IsisRouterA.Basic().SetEnableWideMetric(true)
	IsisRouterA.Basic().SetLearnedLspFilter(true)

	.................................................................................................
        .................................................................................................

      filename := "./input_isis_tlvs.bin"
      fb, err := os.ReadFile(filename)
      if err != nil {
	 // Error
        }
      // ImportConfig defines various import parameters that dictates the import processing.
       importConfig := ImportISISTlv.ImportConfig{		 
		 TlvReplayType: tlvReplay.ProtoFile,  //Later could add .WiresharkPcap for example. Similar to BGP importing update. 
		 TargetIsisRouter: gosnappi.Isis{IsisRouterA}, // Normally one ISIS Router which will advertise these Tlvs to peer.
	       }
      // Get route importer service specific to the import file format
      tlvReplayProtoService, err := routeimporter.GetTlvReplayService(tlvReplay.ProtoFile)
      if err != nil {
	 // Error
      }
      // Import Tlvs based on the config. On success TargetIsisRouter gets updated with replay_tlvs.
      _, err := tlvReplayProtoService.ImportTlvReplay(importConfig, &fb)
      if err != nil {
	 // Error
      }

      replayTlvs := IsisRouterA.ReplayTlvs().Items()
      fmt.Printf("Number of Tlvs imported = %v\n", len(replayTlvs()))

     _//Example appending an area Tlv: Type:1, Length 8_
     IsisRouterA.ReplayTlvs().append("01080349494903494948")

     _//Example appending an extended IP Reachability Tlv of Type: 135 and Length 9_
     IsisRouterA.ReplayTlvs().append("870900000000200c000001")