gtp

Documentation

Overview

Package gtp provides simple and painless handling of GTP(GPRS Tunneling Protocol), implemented in the Go Programming Language.

Examples for specific node are available in examples directory, which can be as it is in the following way. As for the detailed usage as a package, see v0/v1/v2 directory for what you can do with the current implementation.

1. Open four terminals on the same machine and start capturing on loopback interface.

2. Start P-GW on terminal #1 and #2 // on terminal #1 ./pgw

   // on terminal #2 ./pgw -s5c 127.0.0.53:2123 -s5u 127.0.0.5:2152

3. Start S-GW on terminal #3

// on terminal #3
./sgw

4. Start MME on terminal #4

// on terminal #4
./mme

5. You will see the nodes exchanging Create Session and Modify Bearer on C-Plane, and ICMP Echo on U-Plane afterwards.

Index

• Variables
• func Serialize(m Message) ([]byte, error)
• type Message
  • func Decode(b []byte) (Message, error)

Variables

var (
	ErrInvalidVersion      = errors.New("got invalid version")
	ErrInvalidLength       = errors.New("length value is invalid")
	ErrTooShortToDecode    = errors.New("too short to decode as GTP")
	ErrTooShortToSerialize = errors.New("too short to serialize")
)

Common error definitions.

Functions

func Serialize

func Serialize(m Message) ([]byte, error)

Serialize returns the byte sequence generated from a Message instance. Better to use SerializeXxx instead if you know the name of message to be serialized.

Types

type Message

type Message interface {
	SerializeTo([]byte) error
	DecodeFromBytes(b []byte) error
	Len() int
	Version() int
	MessageType() uint8
	MessageTypeName() string
}

Message is an interface that defines all versions of GTP messages.

func Decode

func Decode(b []byte) (Message, error)

Decode decodes given bytes as Message.