Stateless user-plane architecture for virtualized EPC (vEPC) http://tools.ietf.org/html/draft-matsushima-stateless-uplane-vepc-01

Ryuji Wakikawa

Satoru Matsushima

Today

2

RAN Internet

PDN-GW

SGW MME

PCRF

AAA

HSS

EPC Core

Network Function Virtualization

3

RAN

vEPC

PDN-GW

SGW MME

PCRF

AAA

HSS

Core Backbone NW

WHY: All packets incl. control signaling are routed to vEPC.

Internet

Virtualized EPC on Hypervisor

Splitting Control and User Plane

4

RAN

vEPC

Core Backbone NW

Goal: User packets bypass vEPC

Internet

User-plane

Control-Plane

vEPC

Motivation

5

RAN Internet Core

Backbone NW

vEPC creates and manages UE’s state.

A  mechanism  is  required  to  reflect  states  in  Control  plane  to  routers  in  User  plane.•  Routing  protocols  (BGP  in  our  draft)•  Extension  to  Proxy  Mobile  IP  (draft-wakikawa-netext-pmip-cp-up-separation-00.txt)•  SDN/OpenFlow!?•  FORCES  Working  Group

l  Router?l  LMA/MAG?l  vSwitch?

Stateless user-plane architecture

Overview l  Note: any questions regarding 3GPP specific question or

backward compatibility are answered in offline. l  What we support in the draft

l Motivation, Benefits of NFV, Requirements l BGP update between Control and User planes l Handover mechanism l Address delegation mechanism l  IPv4 support mechanism l Backward compatibility: Control plane is untouched.

l When special handling is needed like roaming, packets are routed to vEPC.

vEPC

Configuration

8

RAN

Internet IPv6 Core NW

Router EPC-E

(router)

anycast address (RAN side)

GTP

GTP is established to anycast address of EPC-E

vEPC

Route Update

9

RAN

Internet Operator’s aggregated prefix

GTP

BGP  Update(Normal)

draft-vandevelde-idr-remote-next-hop

BGP  Update  Remote  Next  Hop2001:abcd:efgh::/64

BGP Update Dst: 2001:abcd:efgh::/64 NxtHop: GTP tunnel + TEID (demultiplexer)

BGP Update Dst: 2001:abcd::/32 NxtHop: one of EPC-E

vEPC

Route Update

10

RAN

Internet Operator’s aggregated prefix

GTP

Host  Routes  are  aggregated

Routes  at  all  the  EPC-E

Destination 2001:abcd:efgh::/64

NextHop GTP  tunnel

Routes  at  routers

Destination 2001:abcd::/32

NextHop One  of  EPC-E

2001:abcd:efgh::/64

vEPC

Handover

11

RAN

Internet GTP

Hand-over Signaling

hand-over

New  Routes  at  EPC-E

Destination UE  Prefix

NextHop GTP  tunnel  @New  eNB

draft-vandevelde-idr-remote-next-hop

BGP  Update  Remote  Next  Hop

vEPC

Address Delegation

12

Internet

Destination NextHop

… …

2001:db8::/64 GTP Tunnel

② Reverse Lookup

①　RS or DHCPv6 Req

③　RA or DHCPv6 Res (Delegate 2001:db8::/64)

vEPC

Backward compatibility

13

RAN

Internet IPv6 Core Backbone NW

Router

Operator’s aggregated prefix

EPC-E (router)

anycast address (RAN side)

GTP

GTP is established to legacy EPC located in vEPC cloud.

Hypervisor

PGW SGW

Existing

Core

Roaming Partner

Service network

(IMS, etc)

S8 S5

S4

SGi

Study Items: BGP capability

Source: ISOCORE Technical Report!http://www.cisco.com/en/US/prod/collateral/routers/ps9343/ITD13029-ASR1000-RP2Validationv1_1.pdf

An existing BGP Route Reflector can send over 5M/sec BGP updates!*

*: We still need to investigate statistics of number of handover event in deployed cellular network

vEPC

IPv4 Support

15

Internet

DS-Lite B4 or

464XLAT CLAT (Stateless)

DS-Lite AFTR or

464XLAT PLAT (Stateful)

IPv4 over IPv6 or

v4v6 translation

GTP (IPv4-Only)

IPv4 address allocation

(GTP control-plane)