diff --git a/agent.go b/agent.go
index 9cb14b2..c7f5037 100644
--- a/agent.go
+++ b/agent.go
@@ -908,7 +908,16 @@ func (a *Agent) handleInbound(m *stun.Message, local Candidate, remote net.Addr)
 				return
 			}
 
-			prflxCandidate, err := NewCandidatePeerReflexive(networkType.String(), ip.String(), port, local.Component(), "", 0)
+			prflxCandidateConfig := CandidatePeerReflexiveConfig{
+				Network:   networkType.String(),
+				Address:   ip.String(),
+				Port:      port,
+				Component: local.Component(),
+				RelAddr:   "",
+				RelPort:   0,
+			}
+
+			prflxCandidate, err := NewCandidatePeerReflexive(&prflxCandidateConfig)
 			if err != nil {
 				a.log.Errorf("Failed to create new remote prflx candidate (%s)", err)
 				return
diff --git a/agent_test.go b/agent_test.go
index 01f07e7..20d926e 100644
--- a/agent_test.go
+++ b/agent_test.go
@@ -61,50 +61,63 @@ func TestPairPriority(t *testing.T) {
 		t.Fatalf("Failed to create agent: %s", err)
 	}
 
-	hostLocal, err := NewCandidateHost(
-		"udp",
-		"192.168.1.1", 19216,
-		1,
-	)
+	hostConfig := &CandidateHostConfig{
+		Network:   "udp",
+		Address:   "192.168.1.1",
+		Port:      19216,
+		Component: 1,
+	}
+	hostLocal, err := NewCandidateHost(hostConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct local host candidate: %s", err)
 	}
 
-	relayRemote, err := NewCandidateRelay(
-		"udp",
-		"1.2.3.4", 12340,
-		1,
-		"4.3.2.1", 43210,
-	)
+	relayConfig := &CandidateRelayConfig{
+		Network:   "udp",
+		Address:   "1.2.3.4",
+		Port:      12340,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43210,
+	}
+	relayRemote, err := NewCandidateRelay(relayConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote relay candidate: %s", err)
 	}
 
-	srflxRemote, err := NewCandidateServerReflexive(
-		"udp",
-		"10.10.10.2", 19218,
-		1,
-		"4.3.2.1", 43212,
-	)
+	srflxConfig := &CandidateServerReflexiveConfig{
+		Network:   "udp",
+		Address:   "10.10.10.2",
+		Port:      19218,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43212,
+	}
+	srflxRemote, err := NewCandidateServerReflexive(srflxConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote srflx candidate: %s", err)
 	}
 
-	prflxRemote, err := NewCandidatePeerReflexive(
-		"udp",
-		"10.10.10.2", 19217,
-		1,
-		"4.3.2.1", 43211,
-	)
+	prflxConfig := &CandidatePeerReflexiveConfig{
+		Network:   "udp",
+		Address:   "10.10.10.2",
+		Port:      19217,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43211,
+	}
+	prflxRemote, err := NewCandidatePeerReflexive(prflxConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote prflx candidate: %s", err)
 	}
 
-	hostRemote, err := NewCandidateHost(
-		"udp",
-		"1.2.3.5", 12350,
-		1,
-	)
+	hostConfig = &CandidateHostConfig{
+		Network:   "udp",
+		Address:   "1.2.3.5",
+		Port:      12350,
+		Component: 1,
+	}
+	hostRemote, err := NewCandidateHost(hostConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote host candidate: %s", err)
 	}
@@ -143,21 +156,26 @@ func TestOnSelectedCandidatePairChange(t *testing.T) {
 		t.Fatalf("Failed to set agent OnCandidatePairChange callback: %s", err)
 	}
 
-	hostLocal, err := NewCandidateHost(
-		"udp",
-		"192.168.1.1", 19216,
-		1,
-	)
+	hostConfig := &CandidateHostConfig{
+		Network:   "udp",
+		Address:   "192.168.1.1",
+		Port:      19216,
+		Component: 1,
+	}
+	hostLocal, err := NewCandidateHost(hostConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct local host candidate: %s", err)
 	}
 
-	relayRemote, err := NewCandidateRelay(
-		"udp",
-		"1.2.3.4", 12340,
-		1,
-		"4.3.2.1", 43210,
-	)
+	relayConfig := &CandidateRelayConfig{
+		Network:   "udp",
+		Address:   "1.2.3.4",
+		Port:      12340,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43210,
+	}
+	relayRemote, err := NewCandidateRelay(relayConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote relay candidate: %s", err)
 	}
@@ -204,7 +222,14 @@ func TestHandlePeerReflexive(t *testing.T) {
 		var config AgentConfig
 		runAgentTest(t, &config, func(a *Agent) {
 			a.selector = &controllingSelector{agent: a, log: a.log}
-			local, err := NewCandidateHost("udp", "192.168.0.2", 777, 1)
+
+			hostConfig := CandidateHostConfig{
+				Network:   "udp",
+				Address:   "192.168.0.2",
+				Port:      777,
+				Component: 1,
+			}
+			local, err := NewCandidateHost(&hostConfig)
 			local.conn = &mockPacketConn{}
 			if err != nil {
 				t.Fatalf("failed to create a new candidate: %v", err)
@@ -262,7 +287,14 @@ func TestHandlePeerReflexive(t *testing.T) {
 		var config AgentConfig
 		runAgentTest(t, &config, func(a *Agent) {
 			a.selector = &controllingSelector{agent: a, log: a.log}
-			local, err := NewCandidateHost("tcp", "192.168.0.2", 777, 1)
+
+			hostConfig := CandidateHostConfig{
+				Network:   "tcp",
+				Address:   "192.168.0.2",
+				Port:      777,
+				Component: 1,
+			}
+			local, err := NewCandidateHost(&hostConfig)
 			if err != nil {
 				t.Fatalf("failed to create a new candidate: %v", err)
 			}
@@ -292,7 +324,13 @@ func TestHandlePeerReflexive(t *testing.T) {
 				{tID, &net.UDPAddr{}, false},
 			}
 
-			local, err := NewCandidateHost("udp", "192.168.0.2", 777, 1)
+			hostConfig := CandidateHostConfig{
+				Network:   "udp",
+				Address:   "192.168.0.2",
+				Port:      777,
+				Component: 1,
+			}
+			local, err := NewCandidateHost(&hostConfig)
 			local.conn = &mockPacketConn{}
 			if err != nil {
 				t.Fatalf("failed to create a new candidate: %v", err)
@@ -371,7 +409,13 @@ func TestInboundValidity(t *testing.T) {
 	}
 
 	remote := &net.UDPAddr{IP: net.ParseIP("172.17.0.3"), Port: 999}
-	local, err := NewCandidateHost("udp", "192.168.0.2", 777, 1)
+	hostConfig := CandidateHostConfig{
+		Network:   "udp",
+		Address:   "192.168.0.2",
+		Port:      777,
+		Component: 1,
+	}
+	local, err := NewCandidateHost(&hostConfig)
 	local.conn = &mockPacketConn{}
 	if err != nil {
 		t.Fatalf("failed to create a new candidate: %v", err)
@@ -462,7 +506,13 @@ func TestInboundValidity(t *testing.T) {
 			t.Fatalf("Error constructing ice.Agent")
 		}
 
-		local, err := NewCandidateHost("udp", "192.168.0.2", 777, 1)
+		hostConfig := CandidateHostConfig{
+			Network:   "udp",
+			Address:   "192.168.0.2",
+			Port:      777,
+			Component: 1,
+		}
+		local, err := NewCandidateHost(&hostConfig)
 		local.conn = &mockPacketConn{}
 		if err != nil {
 			t.Fatalf("failed to create a new candidate: %v", err)
@@ -627,50 +677,63 @@ func TestCandidatePairStats(t *testing.T) {
 		t.Fatalf("Failed to create agent: %s", err)
 	}
 
-	hostLocal, err := NewCandidateHost(
-		"udp",
-		"192.168.1.1", 19216,
-		1,
-	)
+	hostConfig := &CandidateHostConfig{
+		Network:   "udp",
+		Address:   "192.168.1.1",
+		Port:      19216,
+		Component: 1,
+	}
+	hostLocal, err := NewCandidateHost(hostConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct local host candidate: %s", err)
 	}
 
-	relayRemote, err := NewCandidateRelay(
-		"udp",
-		"1.2.3.4", 2340,
-		1,
-		"4.3.2.1", 43210,
-	)
+	relayConfig := &CandidateRelayConfig{
+		Network:   "udp",
+		Address:   "1.2.3.4",
+		Port:      2340,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43210,
+	}
+	relayRemote, err := NewCandidateRelay(relayConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote relay candidate: %s", err)
 	}
 
-	srflxRemote, err := NewCandidateServerReflexive(
-		"udp",
-		"10.10.10.2", 19218,
-		1,
-		"4.3.2.1", 43212,
-	)
+	srflxConfig := &CandidateServerReflexiveConfig{
+		Network:   "udp",
+		Address:   "10.10.10.2",
+		Port:      19218,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43212,
+	}
+	srflxRemote, err := NewCandidateServerReflexive(srflxConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote srflx candidate: %s", err)
 	}
 
-	prflxRemote, err := NewCandidatePeerReflexive(
-		"udp",
-		"10.10.10.2", 19217,
-		1,
-		"4.3.2.1", 43211,
-	)
+	prflxConfig := &CandidatePeerReflexiveConfig{
+		Network:   "udp",
+		Address:   "10.10.10.2",
+		Port:      19217,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43211,
+	}
+	prflxRemote, err := NewCandidatePeerReflexive(prflxConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote prflx candidate: %s", err)
 	}
 
-	hostRemote, err := NewCandidateHost(
-		"udp",
-		"1.2.3.5", 12350,
-		1,
-	)
+	hostConfig = &CandidateHostConfig{
+		Network:   "udp",
+		Address:   "1.2.3.5",
+		Port:      12350,
+		Component: 1,
+	}
+	hostRemote, err := NewCandidateHost(hostConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote host candidate: %s", err)
 	}
@@ -746,21 +809,26 @@ func TestLocalCandidateStats(t *testing.T) {
 		t.Fatalf("Failed to create agent: %s", err)
 	}
 
-	hostLocal, err := NewCandidateHost(
-		"udp",
-		"192.168.1.1", 19216,
-		1,
-	)
+	hostConfig := &CandidateHostConfig{
+		Network:   "udp",
+		Address:   "192.168.1.1",
+		Port:      19216,
+		Component: 1,
+	}
+	hostLocal, err := NewCandidateHost(hostConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct local host candidate: %s", err)
 	}
 
-	srflxLocal, err := NewCandidateServerReflexive(
-		"udp",
-		"192.168.1.1", 19217,
-		1,
-		"4.3.2.1", 43212,
-	)
+	srflxConfig := &CandidateServerReflexiveConfig{
+		Network:   "udp",
+		Address:   "192.168.1.1",
+		Port:      19217,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43212,
+	}
+	srflxLocal, err := NewCandidateServerReflexive(srflxConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct local srflx candidate: %s", err)
 	}
@@ -821,41 +889,52 @@ func TestRemoteCandidateStats(t *testing.T) {
 		t.Fatalf("Failed to create agent: %s", err)
 	}
 
-	relayRemote, err := NewCandidateRelay(
-		"udp",
-		"1.2.3.4", 12340,
-		1,
-		"4.3.2.1", 43210,
-	)
+	relayConfig := &CandidateRelayConfig{
+		Network:   "udp",
+		Address:   "1.2.3.4",
+		Port:      12340,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43210,
+	}
+	relayRemote, err := NewCandidateRelay(relayConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote relay candidate: %s", err)
 	}
 
-	srflxRemote, err := NewCandidateServerReflexive(
-		"udp",
-		"10.10.10.2", 19218,
-		1,
-		"4.3.2.1", 43212,
-	)
+	srflxConfig := &CandidateServerReflexiveConfig{
+		Network:   "udp",
+		Address:   "10.10.10.2",
+		Port:      19218,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43212,
+	}
+	srflxRemote, err := NewCandidateServerReflexive(srflxConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote srflx candidate: %s", err)
 	}
 
-	prflxRemote, err := NewCandidatePeerReflexive(
-		"udp",
-		"10.10.10.2", 19217,
-		1,
-		"4.3.2.1", 43211,
-	)
+	prflxConfig := &CandidatePeerReflexiveConfig{
+		Network:   "udp",
+		Address:   "10.10.10.2",
+		Port:      19217,
+		Component: 1,
+		RelAddr:   "4.3.2.1",
+		RelPort:   43211,
+	}
+	prflxRemote, err := NewCandidatePeerReflexive(prflxConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote prflx candidate: %s", err)
 	}
 
-	hostRemote, err := NewCandidateHost(
-		"udp",
-		"1.2.3.5", 12350,
-		1,
-	)
+	hostConfig := &CandidateHostConfig{
+		Network:   "udp",
+		Address:   "1.2.3.5",
+		Port:      12350,
+		Component: 1,
+	}
+	hostRemote, err := NewCandidateHost(hostConfig)
 	if err != nil {
 		t.Fatalf("Failed to construct remote host candidate: %s", err)
 	}
diff --git a/candidate_host.go b/candidate_host.go
index e8b766a..6a80198 100644
--- a/candidate_host.go
+++ b/candidate_host.go
@@ -12,26 +12,40 @@ type CandidateHost struct {
 	network string
 }
 
+// CandidateHostConfig is the config required to create a new CandidateHost
+type CandidateHostConfig struct {
+	CandidateID string
+	Network     string
+	Address     string
+	Port        int
+	Component   uint16
+}
+
 // NewCandidateHost creates a new host candidate
-func NewCandidateHost(network string, address string, port int, component uint16) (*CandidateHost, error) {
-	candidateID, err := generateCandidateID()
-	if err != nil {
-		return nil, err
+func NewCandidateHost(config *CandidateHostConfig) (*CandidateHost, error) {
+	candidateID := config.CandidateID
+
+	if candidateID == "" {
+		var err error
+		candidateID, err = generateCandidateID()
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	c := &CandidateHost{
 		candidateBase: candidateBase{
 			id:            candidateID,
-			address:       address,
+			address:       config.Address,
 			candidateType: CandidateTypeHost,
-			component:     component,
-			port:          port,
+			component:     config.Component,
+			port:          config.Port,
 		},
-		network: network,
+		network: config.Network,
 	}
 
-	if !strings.HasSuffix(address, ".local") {
-		ip := net.ParseIP(address)
+	if !strings.HasSuffix(config.Address, ".local") {
+		ip := net.ParseIP(config.Address)
 		if ip == nil {
 			return nil, ErrAddressParseFailed
 		}
diff --git a/candidate_peer_reflexive.go b/candidate_peer_reflexive.go
index b5a5162..b9417c2 100644
--- a/candidate_peer_reflexive.go
+++ b/candidate_peer_reflexive.go
@@ -1,3 +1,5 @@
+// Package ice ...
+//nolint:dupl
 package ice
 
 import "net"
@@ -7,21 +9,36 @@ type CandidatePeerReflexive struct {
 	candidateBase
 }
 
+// CandidatePeerReflexiveConfig is the config required to create a new CandidatePeerReflexive
+type CandidatePeerReflexiveConfig struct {
+	CandidateID string
+	Network     string
+	Address     string
+	Port        int
+	Component   uint16
+	RelAddr     string
+	RelPort     int
+}
+
 // NewCandidatePeerReflexive creates a new peer reflective candidate
-func NewCandidatePeerReflexive(network string, address string, port int, component uint16, relAddr string, relPort int) (*CandidatePeerReflexive, error) {
-	ip := net.ParseIP(address)
+func NewCandidatePeerReflexive(config *CandidatePeerReflexiveConfig) (*CandidatePeerReflexive, error) {
+	ip := net.ParseIP(config.Address)
 	if ip == nil {
 		return nil, ErrAddressParseFailed
 	}
 
-	networkType, err := determineNetworkType(network, ip)
+	networkType, err := determineNetworkType(config.Network, ip)
 	if err != nil {
 		return nil, err
 	}
 
-	candidateID, err := generateCandidateID()
-	if err != nil {
-		return nil, err
+	candidateID := config.CandidateID
+	if candidateID == "" {
+		var err error
+		candidateID, err = generateCandidateID()
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	return &CandidatePeerReflexive{
@@ -29,13 +46,13 @@ func NewCandidatePeerReflexive(network string, address string, port int, compone
 			id:            candidateID,
 			networkType:   networkType,
 			candidateType: CandidateTypePeerReflexive,
-			address:       address,
-			port:          port,
-			resolvedAddr:  &net.UDPAddr{IP: ip, Port: port},
-			component:     component,
+			address:       config.Address,
+			port:          config.Port,
+			resolvedAddr:  &net.UDPAddr{IP: ip, Port: config.Port},
+			component:     config.Component,
 			relatedAddress: &CandidateRelatedAddress{
-				Address: relAddr,
-				Port:    relPort,
+				Address: config.RelAddr,
+				Port:    config.RelPort,
 			},
 		},
 	}, nil
diff --git a/candidate_relay.go b/candidate_relay.go
index 7a983e1..7192377 100644
--- a/candidate_relay.go
+++ b/candidate_relay.go
@@ -17,19 +17,35 @@ type CandidateRelay struct {
 	permissions map[string]*turnc.Permission
 }
 
+// CandidateRelayConfig is the config required to create a new CandidateRelay
+type CandidateRelayConfig struct {
+	CandidateID string
+	Network     string
+	Address     string
+	Port        int
+	Component   uint16
+	RelAddr     string
+	RelPort     int
+}
+
 // NewCandidateRelay creates a new relay candidate
-func NewCandidateRelay(network string, address string, port int, component uint16, relAddr string, relPort int) (*CandidateRelay, error) {
-	ip := net.ParseIP(address)
+func NewCandidateRelay(config *CandidateRelayConfig) (*CandidateRelay, error) {
+	candidateID := config.CandidateID
+
+	if candidateID == "" {
+		var err error
+		candidateID, err = generateCandidateID()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	ip := net.ParseIP(config.Address)
 	if ip == nil {
 		return nil, ErrAddressParseFailed
 	}
 
-	networkType, err := determineNetworkType(network, ip)
-	if err != nil {
-		return nil, err
-	}
-
-	candidateID, err := generateCandidateID()
+	networkType, err := determineNetworkType(config.Network, ip)
 	if err != nil {
 		return nil, err
 	}
@@ -39,13 +55,13 @@ func NewCandidateRelay(network string, address string, port int, component uint1
 			id:            candidateID,
 			networkType:   networkType,
 			candidateType: CandidateTypeRelay,
-			address:       address,
-			port:          port,
-			resolvedAddr:  &net.UDPAddr{IP: ip, Port: port},
-			component:     component,
+			address:       config.Address,
+			port:          config.Port,
+			resolvedAddr:  &net.UDPAddr{IP: ip, Port: config.Port},
+			component:     config.Component,
 			relatedAddress: &CandidateRelatedAddress{
-				Address: relAddr,
-				Port:    relPort,
+				Address: config.RelAddr,
+				Port:    config.RelPort,
 			},
 		},
 		permissions: map[string]*turnc.Permission{},
diff --git a/candidate_server_reflexive.go b/candidate_server_reflexive.go
index c7ca3e2..e50e5e3 100644
--- a/candidate_server_reflexive.go
+++ b/candidate_server_reflexive.go
@@ -7,21 +7,35 @@ type CandidateServerReflexive struct {
 	candidateBase
 }
 
+// CandidateServerReflexiveConfig is the config required to create a new CandidateServerReflexive
+type CandidateServerReflexiveConfig struct {
+	CandidateID string
+	Network     string
+	Address     string
+	Port        int
+	Component   uint16
+	RelAddr     string
+	RelPort     int
+}
+
 // NewCandidateServerReflexive creates a new server reflective candidate
-func NewCandidateServerReflexive(network string, address string, port int, component uint16, relAddr string, relPort int) (*CandidateServerReflexive, error) {
-	ip := net.ParseIP(address)
+func NewCandidateServerReflexive(config *CandidateServerReflexiveConfig) (*CandidateServerReflexive, error) {
+	ip := net.ParseIP(config.Address)
 	if ip == nil {
 		return nil, ErrAddressParseFailed
 	}
 
-	networkType, err := determineNetworkType(network, ip)
+	networkType, err := determineNetworkType(config.Network, ip)
 	if err != nil {
 		return nil, err
 	}
 
-	candidateID, err := generateCandidateID()
-	if err != nil {
-		return nil, err
+	candidateID := config.CandidateID
+	if candidateID == "" {
+		candidateID, err = generateCandidateID()
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	return &CandidateServerReflexive{
@@ -29,13 +43,13 @@ func NewCandidateServerReflexive(network string, address string, port int, compo
 			id:            candidateID,
 			networkType:   networkType,
 			candidateType: CandidateTypeServerReflexive,
-			address:       address,
-			port:          port,
-			resolvedAddr:  &net.UDPAddr{IP: ip, Port: port},
-			component:     component,
+			address:       config.Address,
+			port:          config.Port,
+			resolvedAddr:  &net.UDPAddr{IP: ip, Port: config.Port},
+			component:     config.Component,
 			relatedAddress: &CandidateRelatedAddress{
-				Address: relAddr,
-				Port:    relPort,
+				Address: config.RelAddr,
+				Port:    config.RelPort,
 			},
 		},
 	}, nil
diff --git a/gather.go b/gather.go
index 5f8d16e..ad7a7c5 100644
--- a/gather.go
+++ b/gather.go
@@ -182,7 +182,15 @@ func (a *Agent) gatherCandidatesLocal(networkTypes []NetworkType) {
 				}
 
 				port := conn.LocalAddr().(*net.UDPAddr).Port
-				c, err := NewCandidateHost(network, address, port, ComponentRTP)
+
+				hostConfig := CandidateHostConfig{
+					Network:   network,
+					Address:   address,
+					Port:      port,
+					Component: ComponentRTP,
+				}
+
+				c, err := NewCandidateHost(&hostConfig)
 				if err != nil {
 					a.log.Warnf("Failed to create host candidate: %s %s %d: %v\n", network, ip, port, err)
 					return
@@ -249,7 +257,16 @@ func (a *Agent) gatherCandidatesSrflx(urls []*URL, networkTypes []NetworkType) {
 			port := xoraddr.Port
 			relIP := laddr.IP.String()
 			relPort := laddr.Port
-			c, err := NewCandidateServerReflexive(network, ip.String(), port, ComponentRTP, relIP, relPort)
+
+			srflxConfig := CandidateServerReflexiveConfig{
+				Network:   network,
+				Address:   ip.String(),
+				Port:      port,
+				Component: ComponentRTP,
+				RelAddr:   relIP,
+				RelPort:   relPort,
+			}
+			c, err := NewCandidateServerReflexive(&srflxConfig)
 			if err != nil {
 				a.log.Warnf("Failed to create server reflexive candidate: %s %s %d: %v\n", network, ip, port, err)
 				continue
@@ -314,7 +331,15 @@ func (a *Agent) gatherCandidatesRelay(urls []*URL) error {
 		ip := allocation.Relayed().IP
 		port := allocation.Relayed().Port
 
-		candidate, err := NewCandidateRelay(network, ip.String(), port, ComponentRTP, laddr.IP.String(), laddr.Port)
+		relayConfig := CandidateRelayConfig{
+			Network:   network,
+			Address:   ip.String(),
+			Port:      port,
+			Component: ComponentRTP,
+			RelAddr:   laddr.IP.String(),
+			RelPort:   laddr.Port,
+		}
+		candidate, err := NewCandidateRelay(&relayConfig)
 		if err != nil {
 			a.log.Warnf("Failed to create server reflexive candidate: %s %s %d: %v\n", network, ip, port, err)
 			continue
diff --git a/transport_test.go b/transport_test.go
index d365888..401e7d6 100644
--- a/transport_test.go
+++ b/transport_test.go
@@ -331,14 +331,40 @@ func pipeWithTimeout(iceTimeout time.Duration, iceKeepalive time.Duration) (*Con
 }
 
 func copyCandidate(o Candidate) (c Candidate) {
+	candidateID := o.ID()
 	var err error
 	switch orig := o.(type) {
 	case *CandidateHost:
-		c, err = NewCandidateHost(udp, orig.address, orig.port, orig.component)
+		config := CandidateHostConfig{
+			CandidateID: candidateID,
+			Network:     udp,
+			Address:     orig.address,
+			Port:        orig.port,
+			Component:   orig.component,
+		}
+		c, err = NewCandidateHost(&config)
 	case *CandidateServerReflexive:
-		c, err = NewCandidateServerReflexive(udp, orig.address, orig.port, orig.component, orig.relatedAddress.Address, orig.relatedAddress.Port)
+		config := CandidateServerReflexiveConfig{
+			CandidateID: candidateID,
+			Network:     udp,
+			Address:     orig.address,
+			Port:        orig.port,
+			Component:   orig.component,
+			RelAddr:     orig.relatedAddress.Address,
+			RelPort:     orig.relatedAddress.Port,
+		}
+		c, err = NewCandidateServerReflexive(&config)
 	case *CandidateRelay:
-		c, err = NewCandidateRelay(udp, orig.address, orig.port, orig.component, orig.relatedAddress.Address, orig.relatedAddress.Port)
+		config := CandidateRelayConfig{
+			CandidateID: candidateID,
+			Network:     udp,
+			Address:     orig.address,
+			Port:        orig.port,
+			Component:   orig.component,
+			RelAddr:     orig.relatedAddress.Address,
+			RelPort:     orig.relatedAddress.Port,
+		}
+		c, err = NewCandidateRelay(&config)
 	default:
 		panic("Tried to copy unsupported candidate type")
 	}