Advances in IPv6 Mobile Access - gogoNET LIVE!

Company ConfidentialAdvances in IPv6Mobile AccessJohn Loughney, Nokiajohn.loughney@nokia.com(with help from Teemu Savolainen, Nokia)

Company ConfidentialOverviewMotivations for IPv6 in mobile networksMain IPv6 Deployment options in mobile networksHandset support for IPv6Network support for IPv6Key challengesPractical advice

Company ConfidentialMotivations• 5.3 billion mobile subscribers, ITU-T figures for 2010.• Large percentage are IP capable−Trend toward Always-On applications (details next slide)• LTE is happening now, will be soon doing voice over IP only.• Operators run both a circuit switched and IP networks,causing higher CAPEX and OPEX.• In the future, services will migrate to IP.• Carrier grade NATs are a misnomer.• So the choice is between−IPv4 with NAT frequent keep-alives & additional investments−IPv6 and long lived connections

Company ConfidentialNATs with keep alive messages• IPv4 Mobile Devices are usually behind IPv4 NATs−Always on application are becoming more prevalent−Applications that want to be reachable need to sendperiodic keep-alives to keep NAT state active− Current NATs require keep-alives from 40 seconds to 5 minutes− Need to implement for minimum (~30 seconds)• Sending of NAT periodic keep-alive messages decreases mobiledevice standby time by several days• Not a problem for devices with power cords, but for mobile devices itis a big problemClient, PrivateIPv4 address 1There should be NONATs between theterminal and theserver!Client, PrivateIPv4 address 2 UDP port = 6538The UDP inactivity timer in NATs causes thepublic UDP port 6538 to be assigned to adifferent mobile, if the mobile does not send anydata within a certain amount of time, about every40 seconds …Server, Public IPv4 address 3

Company ConfidentialIPv6 Trial Checklist• IPv6 enabled routers and switches• IPv6 transit provider and peering• IPv6 enabled hosts• IPv6 enabled apps• Address planning, address config, DNS• Transition mechanism(s) selection• Fallback planning• Middlebox support (firewalls, proxies, etc.)5 © Nokia 2011 Filename.pptx v. 0.1 YYYY-MM-DD Author Document ID [Edit via Insert > Header & Footer]

Deployment approachesDual-stack approach is the mostcustomer-friendly solution fortransitioning to IPv6Dual-stack is also the standardapproach (3GPP) and appears to bethe most favored approachIPv6-only transition solution based onprotocol translation can cause servicediscontinuity, and is only an option forspecific cases due to discrete reasons6Company Confidential

Details of dual-stack3GPP release-8 introduced a new bearertype: IPv4v6IPv4 and IPv6 bearers can be used inparallel when IPv4v6 is not supported(since 3GPP release-99)Various fallback scenarios are involvedthat are not present with IPv4-onlydevices, e.g. IPv4v6 -> IPv4 & IPv67References: 3GPP release-8 23.060, 23.401draft-ietf-v6ops-3gpp-epsCompany Confidential

Details of IPv6-onlyEverything, including applications, MUST BEIPv6 enabled – otherwise solutions such asNAT46 on a host (aka BIH) may be neededIPv6 is not always available: no supporton visited network, blocked on purposedue lack of roaming agreements..Fallback support to IPv4-only mode ismandatoryThis is pretty much the end-scenarioworld is transitioning towards8Company Confidential

Company ConfidentialIPv6 impacts at all levelsServices & ContentApplicationsGoogle, YouTube, Akamai, Facebook, Bing, ...Browsers, E-mail, IM, VoIP, Games, Utilities,Middleware entities like HTTP, ...API Qt, Java, Posix, Symbian & other OS APIs, ...TCP/IP StackModemSymbian, iOS, Android, Windows Phone,various flavors of Linux, Series 40, RIM,Renesas, Qualcomm, ST-E, GCT, Broadcom,Icera (Nvidia), Marvell, Infineon, MediaTek, ...

IPv6 on handsetsIPv6 support requiredat different levelsIPv6 support on the applicationsIPv6 support on APIsIPv6 support on the connection managerIPv6 support on the TCP/IP stackIPv6 support on the modem10Company Confidential

Status of terminalsIPv6 support requiredby the businessIPv6 support on the applicationsIPv6 support on APIsIPv6 support on the connection managerIPv6 support on the TCP/IP stackIPv6 support on the modem11Company Confidential

Company ConfidentialPhone support for IPv6LG VL600CDMA/LTEdongleAndroidMotorola DroidBionic handset forVerizonReportedly has haveIPv6 for cellular.Samsung Nexus SHas IPv6 for WLANonly.iPhone 4SIPv6 for WLANonlyWindows Phone 7MangoIPv4 only as no IPv6yet on WP OS;coming in ApolloSymbianHas supported IPv6since 2004, and usedin trials. Apps canuse IPv4 or IPv6cellular access butnot bothsimultaneously. Thisworks normally whenusing WiFi access.Nokia N9IPv6 add-onenables dualstackin 3G andWiFi accesses.Nokia 21M-022G/3G /3.5G USBdongleSupports IPv6 andIPv4v6 PDP types

Company ConfidentialHigh level cellular requirements• Dual-stack with single PDP (IPv6v4) is the most common solution• Some network operators are considering dual-stack with parallel PDPs(IPv6 & IPv4).− It is required for a 3GPP fallback scenario.• IPv6-only solution is also required by a few• Other solutions are also queried and investigated, but not required yet− PNAT, DS-Lite, DSMIP6, A+P & DS-Lite, 6rd.• Configurability to single PDP (IPv4v6), parallel PDPs (IPv6 & IPv4), or onlyIPv6− OMA DM (operator configuration) for APN setting• Gradual fallback in roaming and error cases for improved user experience− IPv4v6 ► IPv4 & IPv6 ► IPv4 or IPv6− IPv6 ► IPv4

IPv6 status on mobile networks• Closed IPv6 trials at least since 2003• First commercial IPv6 deployments at 2010− While many operators are conducting internal (lab) trials• Public trials and some commercial deployments occurringduring 2011− Even more operators are trialing− Number of cellular IPv6 capable devices also increasing• And things are getting even better for 2012 !• But there are some gotchas14Company Confidential

Company ConfidentialGotchas15

Company ConfidentialDNS server address discovery• This has been a difficult topic in IETF...• 3GPP cellular access1. MUST take the address from PDP activation2. Stateless DHCPv6 can be optionally supported3. RA based approach can be supported but as not included in3GPP specs, it is not something that can be depended upon.• WiFi access1. Stateless DHCPv6 is currently most widely available2. RA based solution will probably be increasingly available asstandard RFC6106 exists (and e.g. RADVD supports thishence Linux based routers can easily have this)• In the dual-stack case, it is just fine to talk to the DNS serverover IPv4, but IPv6 should be preferred (as general principle)

Company ConfidentialDNS query sending procedures• Four possibilities for querying IPv4 and IPv6 addresses:1) AAAA and A sequentially (Android, Maemo, Ubuntu)2) A and AAAA sequentially (Windows 7, Symbian)3) AAAA and A parallel4) A and AAAA parallel (iOS, OS/X)• Use of 3 or 4 avoids extra RTT in dual-stack networks• The approach of sending A first is due to some legacy DNSservers screwing up if they get AAAA followed by A.. So A firstmay be slightly safer.• Important to prefer IPv6 when both can be used

Company Confidential”Happy Eyeballs”Endpoints issue DNS queries for AAAA and A resourcerecords and then attempts connections to IPv6 andIPv4 addresses sequentially. If the IPv6 path is broken(or slow), it can take a long time before it falls back toIPv4 resulting in delays from 20 seconds to severalminutes if the IPv6 path is broken.Apps can improve the user experience by moreaggressively making connections on IPv6 and IPv4by using a variety of algorithms.In this approach, the application makes itsconnection attempts more aggressively over bothIPv6 and IPv4. Initially, the connection attempts aremade in order to provide a fast user experienceDNShostDual-StackWLANFWDual-StackInternetWWW1)IPv6Silent drop2)IPv6ICMPv6 no route3)IPv6ICMPv6 address unreachable

IPv6 changes tethering significantlyTraditional dial-up style IPv4tethering uses dedicated PDPcontext for the dial-upTraditional dial-up is possiblealso with IPv6IPv4 tethering solutions, often useNAT and DHCP to allow sharing ofthe same mobile connection withinternal applicationsIPv6 does not use NATting, but instead NeighborDiscovery Proxy ”bridging function” that does not requireexplicit network support, or explicit and more properDHCPv6 Prefix Delegation as is defined in 3GPPRelease-1019Company Confidential

Bridging and DHCPv6 illustrated”Bridging” with Neighbor DiscoveryProxy – no explicit network support isrequired!PDN GWDHCPv6 Prefix Delegation – supportincluded in 3GPP since Release-10PDN GW &DHCPv6 serverPDP2001:0db8:0:1::/64PDP2001:0db8:0:1::/64f(”proxy”)Sameprefix onboth linksf(”router”)Handset(possibly with DHCPv6 server)Delegated e.g. 2001:0db8::/562001:0db8:0:1::/642001:0db8:0:81::/642001:0db8:0:C1::/64WLANWLANf(”router”)WLAN20Company Confidential

Illustration of basic WiFioffloading technologiesunder studyInternetWiFi accessCellular operator’sservicesRoutingrule DBRules via DHCPv6CellularaccessProvisioning rules with OMA-DMDHCPv6server21RFC4191draft-ietf-mif-dhcpv6-route-optiondraft-ietf-mif-dns-server-selectiondraft-korhonen-mif-ra-offload3GPP 24.312 ANDSFRules via IPv6 Router AdvertisementsCompany ConfidentialAccess NetworkDiscovery and SelectionFunction(ANDSF) PDN GW

IPv6 standards are readyKey specifications and standards are complete andmatured for product creation and deploymentAdditional features and improvements areactively researched, developed, and standardized. Nokiaparticipates, for example, to: IPv6 protocol maintenance,Multi-Interface improvements, IP mobility solutions,protocol translation topics, and Happy Eyeballs22Company Confidential

Company ConfidentialRecommendations• Networks are getting deployed – use them• Get a handset that supports IPv6 on both cellular and wifi• Make sure you have apps that can speak both IPv4 and IPv6−Don’t make address assumptions−Address assignments are handled differently depending whatinterface is used• Make sure your apps implement a ‘happy eyeballs’ algorithm