ipv6 in 3gpp evolved packet system draft-korhonen-v6ops-3gpp-eps-04
DESCRIPTION
IPv6 in 3GPP Evolved Packet System draft-korhonen-v6ops-3gpp-eps-04. Jouni Korhonen , Jonne Soininen , Basavaraj Patil , Teemu Savolainen , Gabor Bajko , Kaisu Iisakkila V6OPS IETF #79. Overview. Describes 3GPP Release-8 Evolved Packet System and Evolved Packet Core architectures. - PowerPoint PPT PresentationTRANSCRIPT
IPv6 in 3GPP Evolved Packet System
draft-korhonen-v6ops-3gpp-eps-04
Jouni Korhonen, Jonne Soininen, Basavaraj Patil, Teemu Savolainen,
Gabor Bajko, Kaisu Iisakkila
V6OPS IETF #79
Overview Describes 3GPP Release-8 Evolved Packet
System and Evolved Packet Core architectures. And some Release-9 and -10 IPv6 related features.
Explains how IPv6 is supported in the architecture and the different types of bearers.
Explains some of the basic concepts and terminology of 3GPP IP access.
Mostly about “what is already there ” not about all possible enhancements..
Some Common Terminology.. EPC = Evolved Packet Core RAN = Radio Access Network EPS = Evolved Packet System (EPC + RAN) eNodeB = evolved NodeB i.e. base station in EPS 3GPP Access = radio system developed by 3GPP Non-3GPP Access = radio system not developed by 3GPP UE = User Equipment i.e., a mobile host, wireless device APN = Access Point Name PDN = Packet Data Network i.e. an IP network SGSN = Serving GPRS Support Node GGSN = Gateway GPRS Support Node SGW = Service Gateway PDN-GW = Packet Data Network Gateway MME = Mobility Management Entity Release-x = named version of the GPRS/EPS architecture (eg. Rel-8, Rel-9 etc)
Basic Evolved Packet System Architecture Architecture supports EUTRAN and legacy 2G/3G accesses
as well. PtP link is established between the UE and the P-GW. User-plane traffic always tunneled over the transport network. User-plane addressing independent of transport network
addressing and IP versions.
PDN-GWSGW
MME
eNodeBUE
S1-MME S11
S1-U S5/S8LTE-Uu
Dual-Stack EPS Bearer
PDN / IP ServicesSGi
PDN Connection A PDN Connection is an association between an UE and a PDN,
represented by one IPv4 address and/or one /64 IPv6 prefix. A PDN is identified by an APN and a PDN is accessed via a PDN-GW A PDN is responsible for the IP address/prefix management. On an UE a PDN Connection is equivalent (or visible to an IP stack) as a
network interface. Pre-Release-8 “equivalent” for a PDN Connection is the PDP Context
(used in GPRS).
PDN-GWUE
S5/S8
PDN
SGi
Operator Core & RAN
UE sees the PDN Connection as an interface with an
address/prefix that belongs to the PDN..
PDN-GW is UE’s first-hop router and mobility
anchor for the address/prefix..
Point-to-point connection
Addresses/prefixes belong topologically
to a PND..
APN points to a specific PDN-GW and “names” the
PDN..
EPS Bearer Model A logical concept of a bearer has been
defined as an aggregate of one or more IP flows related to one or more services.
The EPS bearer is between the UE and the PDN-GW, and used to transport IP (v4 and/or v6) packets.
The UE performs the binding of the UL IP flows and the PDN-GW performs the binding of the DL IP flows.
Access Point Name concept UEs and network use APNs to identify a network (e.g.
internet, corporate intra-network, etc) and to some extent the associated services in that network. Example “internet.example.com”
APNs are piggybacked on the administration of the DNS namespace. Release-8 uses extensively S-NAPTR, where are pre-Release-8 was just A/AAAA.
During the connection (bearer) setup, APNs are used (by SGSN/MME) to discover the gateway (GGSN/PDN-GW) that provides the IP connectivity to the network identifier by the APN, supported protocols, topological location collocation properties of gateways.
Access Point Name concept cont’d UE would just request an APN e.g. for
“internet” or request nothing.. MME either figures out the “default” APN for
the UE/subscriber.. or ..MME would substitute a full domain name
of the APN received from the UE MME would then:
Query a NAPTR for the domain Select the NAPTR which matches the required
protocols and such.. Query A/AAAA for both SGW and PDN-GW Push the “selected” PDN-GW address to
“selected“ SGW
PDN-GWSGW
MME
eNodeBUE
S11
S5/S8 PDN / IP ServicesSGi
DNS
$ORIGIN epc.mnc123.mcc345.3gppnetwork.org. ...internet.apn IN NAPTR 10 1 "a" "x-3gpp-pgw:x-s5-gtp" "" topoff.b1.gw1.nodes IN NAPTR 20 2 "a" "x-3gpp-pgw:x-s5-pmip” "" topoff.b1.gw2.nodes...
topoff.b1.gw1.nodes IN A 192.0.2.113 IN A 192.0.2.114 IN AAAA 2001:db8:0:c:0:0:0:0 IN AAAA 2001:db8:0:d:0:0:0:0topoff.b2.gw2.nodes IN A 192.0.2.143 IN A 192.0.2.144 IN AAAA 2001:db8:0:2a:0:0:0:0...
IP configuration and address management IPv4 Address Configuration.
Two methods: DHCPv4 or within the EPS bearer setup signaling (the common way)
DHCP is optional on both the UE and the P-GW. IPv6 Address Configuration.
One method: Stateless Address Autoconfiguration after the bearer setup.
A single /64 prefix is only supported. Additional configuration either using:
Stateless DHCPv[46]; or Using protocol configuration options during NAS signaling
(“layer-2” control signaling).
EPS Bearer Types IPv4 only bearer.
The bearer is configured with one IPv4 address. The link is “IPv4 only”.
IPv6 only bearer. The bearer is configured with one /64 prefix. The link is “IPv6 only”.
IPv4v6 bearer. The bearer is configured with both IPv4 address and one /64 prefix. New bearer type since Release-8. The link is “dual-stack”. V4v6 bearer type is the default in Rel-8 and beyond Rel 9 has also introduced the DS PDP context type for UTRAN and
EDGE
PDN Connection Establishment
1. Attach request2. Auth/AuthZ phase3. Create Session Request4. Create Session Response5. Initial context setup
request/Attach accept6. Radio bearer reconfig7. Initial context setup
response8. Direct transfer9. Attach complete10. UE starts sending UL data11. Modify bearer request12. Modify bearer response13. DL data transmission starts
UE eNodeB MME SGW PDN-GE HSS/AAA
Authentication and Authorization
RB Setup
1)1)
2)
3)3)
4)
5)4)
6)
7)8)
9)
10)
11)
12)
13)
UL Data
DL Data
Address/prefixallocation
Dual-Stack Approach for IP Access Networks prior to Release-8
Dual-stack connectivity possible by opening two parallel PDP Contexts of types IPv4 and IPv6.
Shows up as two separate layer-2 connections. Networks from Release-8 onwards.
A single IPv4v6 PDN Connection in addition to having separate v4 and v6 PDN connections.
Shows up as one layer-2 connection with both IPv4 and IPv6 addresses to the IP stack.
A peek to Release-9 and -10 Release-9 will introduce IPv4v6 PDP Context
type also for GPRS (i.e. 3G, HSPA, ..): Means Gn/Gp interfaces and GTPv1 are updated
to understand the new PDP Type. Release-10 will introduce prefix delegation:
Based on RFC3633. Due 3GPP link model and architectural decisions
some more work in IETF is needed. See draft-ietf-dhc-pd-exclude.
Dual-stack approach
NodeB/BTSeNodeB
S-GW
MME
P-GW
DS-PDN
Type v4v6 PDN connection
NodeB/BTSBS
SGSN
GGSN
IPv4-PDNIPv4-APNIPv4-PDP Context
GGSN
IPv6-APNIPv6-PDN
IPv6-PDP Context
In Rel 8 and beyond networks
In Pre Rel 8 networks