diff --git a/common/net/network.go b/common/net/network.go
index 64efe110..7dbc9316 100644
--- a/common/net/network.go
+++ b/common/net/network.go
@@ -5,10 +5,14 @@ import (
 )
 
 const (
+	// TCPNetwork represents the TCP network.
 	TCPNetwork = Network("tcp")
+
+	// UDPNetwork represents the UDP network.
 	UDPNetwork = Network("udp")
 )
 
+// Network represents a communication network on internet.
 type Network serial.StringLiteral
 
 func (this Network) AsList() *NetworkList {
@@ -16,8 +20,10 @@ func (this Network) AsList() *NetworkList {
 	return &list
 }
 
+// NetworkList is a list of Networks.
 type NetworkList []Network
 
+// NewNetworkList construsts a NetWorklist from the given StringListeralList.
 func NewNetworkList(networks serial.StringLiteralList) NetworkList {
 	list := NetworkList(make([]Network, networks.Len()))
 	for idx, network := range networks {
@@ -26,6 +32,7 @@ func NewNetworkList(networks serial.StringLiteralList) NetworkList {
 	return list
 }
 
+// HashNetwork returns true if the given network is in this NetworkList.
 func (this *NetworkList) HasNetwork(network Network) bool {
 	for _, value := range *this {
 		if string(value) == string(network) {