Private DNS for Mobile Operators

Transcription

1 Private for James Yu Senior Director - Strategic Technical Initiatives NeuStar, Inc. james.yu@neustar.biz (B) (M) Richard Xu Chief Architect Aicent, Inc richard.xu@aicent.com x529 (B) (M) What Is the Domain Name System? The domain name system () is an Internet service that retrieves the resources associated with a domain name. Its initial purpose was to map a domain name to an IP address. The IP address could be the address of a server that provides applications such as web pages, s and VoIP calls. Internet is based on IP address for addressing and routing; however, IP address is not easy for people to remember. So alphanumeric domain names are used instead. was developed to be extensible to manage the domain name space (e.g., hierarchical tree structure). Every time you use a domain name, must translate the name into the corresponding IP address. For example, the domain name example.com might translate to IP address was expanded for many other functions such as locating the SIP servers or mail servers and accessing services on the internet. 2 1

2 General Packet Radio Service (GPRS) GPRS is a 2.5G standard for the GSM system to support packet data service. Serving GPRS Support Node (SGSN) keeps track of mobile stations location and performs security functions and access control. It is connected to the base stations via Frame Relay Gateway GPRS Support Node (GGSN) provides interworking (e.g., routing, address allocation, user authentication and tunneling) with external packet-switch networks. GGSN works as an anchor for IP traffic. MSC/VLR E Gb Gs D TE MT BSS SGSN GGSN PDN TE Gn R Um Gn Gf Gp EIR SGSN A Signalling Interface GPRS reference model SMS-GMSC SMS-IWMSC GGSN Gd Other PLMN Signalling and Data Transfer Interface C Gr HLR SM-SC Gc Gi 3 GPRX Roaming exchange (GRX) SSGN is located at the visited GPRS network and GGSN is normally located at the home GPRS network. GGNS and SGSN are connected via an IP-based backbone network Routing GPRS traffic over Internet may result in poor QoS Secure connectivity between the SGSN and GGSN would require NxN relationships and NxN pipes among the GPRS operators, too many to manage GRX was born to solve GPRS operators problem An GPRS operator has the options of routing the GPRS traffic Over dedicated links (usually for domestic traffic) Over GRX Both 4 2

3 End-to-end GPRS Roaming via GRX Internet Intranet Service PDP Context Activation: MS SGSN GGSN GGSN GPRS Home PLMN BG GTP Tunnel GRX BG Visited GPRS PLMN SGSN TLD 5 GPRS/GRX Leveraging to Locate GGSN SGSN relies on to locate either local GGSN or foreign GGSN in data roaming scenario Access Point Name (APN) provisioned to each MS by home network is used to generate query string for identifying GGSN APN Contains the user s and network s desired routing access preference and is used to create the logical connection between the mobile station and external PDN. Network ID points to the access point within a GPRS Operator Operator ID points to a GPRS Operator <network id>.mnc<mnc>.mcc<mcc>.gprs Network Id Operator Id TLD.gprs, a private suffix, is used with the APN to retrieve the IP address of the GGSN 6 3

4 GRX Hierarchy Private to GPRS Operators. gprs grx mcc111 Managed by GSMA/GRX mnc222 Managed by GPRS Operator APN=internet mms internet.mnc222.mcc111.gprs. <IP of the operator GGSN> mms.mnc222.mcc111.gprs. <IP of MM4 Interface of MMSC> 7 Query Example in GPRS Roaming query whilst roaming APN resolution using in HPLMN 2 GPRS Root 3 4 VPLMN BG 5 HPLMN 1 6 GRX Backbone BG VSGSN BSS 1 Query String: internet.mnc222.mcc111.gprs. 8 4

5 Locating GGSN Steps 1. SGSN sends a query to the resolver for the A RR of internet.mnc222.mcc111.gprs. 2. resolver sends the query to GRX root server for the A RR of internet.mnc222.mcc111.gprs. 3. GRX root server returns the NS RRs and A RRs for mnc222.mcc111.gprs. to the resolver where the NS RRs identify the home GPRS network s servers. 4. resolver sends the query to one of the home GPRS network s server for the A RR of internet.mnc222.mcc111.gprs. 5. Home GPRS network s server returns the A RR of internet.mnc222.mcc111.gprs. to the resolver. 6. resolver returns the A RR of internet.mnc222.mcc111.gprs. to SGSN SGSN now has the IP address of GGSN and can establish a packet data session with GGSN. The packet data session is then established between SGSN and GGSN, and user traffic is tunneled via the GRX(s) or over direct connection between SGSN and GGSN. 9 Global Reach Enabled via GRX Peering O p erato r A O p e ra to r B O p era to r C G P R S R o a m in g N etw o rk G R X G R X D N S D N S D N S O p era to r D O p e ra to r G G R X O p e ra to r E O p erato r F 10 5

6 GRX Peering Architecture at AMS-IX All the IP addresses involved in GRXs are invisible to the Internet (not routable in the Internet) AMS-IX Virtual LAN High-speed, highly redundant optical network Every GRX network has no connection with the Internet GRX A GRX B... GRX Z Some mobile operators use two GRX carriers for redundancy 11 GSMA Structure GSMA Master Root Master Root GRX A GRX B... GRX Z 12 6

7 Domain Name Registration NeuStar Secondary Secondary Master Registry Master Registry Data replication NeuStar Primary Primary Master Registry Master Registry Back up Normal case Internet GRX Carriers & - Web-based portal for registration - Each GRX carrier or mobile operator has accounts with NeuStar - Secure ID card for for log in - Domain name can be * IMSI-derived * Human readable 13 GSMA Operation Zone Transfer NeuStar Master Root Master Root Zone file updates NeuStar Master Master Registry Registry AMS-IX Virtual LAN Both full zone transfer (AXFR) and incremental zone transfer (IXFR) are supported GRX A GRX B... GRX Z 14 7

8 GRX Status There are about two dozen GRX carriers. Some big mobile operators such as Cable & Wireless, France Telecom and TeliaSonera are also GRX carriers. A mobile operator s GRX can serve just itself or itself and others. All the GRX carriers peer at the AMS-IX in Amsterdam. Connections to the Virtual LAN (VLAN) via four collocation facility providers. A GRX carrier accesses VLAN via two separate locations. There is a second peering point in Singapore at Pacific Internet (PacNet); however, only two GRX carriers peer there now. Traffic from an Asian mobile operator to another Asian mobile operator by those two GRX carriers need not go all the way to Amsterdam then back to Asia There are discussions to change the peering point to another provider. 15 Expanding Beyond GPRS Service GPRS is extended to support many other services among GSM community is added to resolve number based addressing used in MMS and inter-working MMS Phone number in the destination address IMS/SIP, and inter-working IMS service TEL URI in SIP signaling is used to support Mobile Number Portability (MNP) associated with phone number based addressing 16 8

9 Operator within GPRS Hierarchy Extending existing GRX hierarchy to support GRX Root Root net gprs Local e164enum mccxxx mncxxx GPRS mncxxx.mccxxx.gprs. APN1 4.4 (UK) (NANP) (CN) e164enum.net mms GSMA / Structure e164enum.net Tier0/1 Tier0/1 GSMA Master Root Master Root e164enum.net GRX A GRX B... GRX Z Tier2 Tier2 Mobile Operators Tier2 Tier e164enum.net 18 9

10 for Inter-Working MMS in GSM Community Pure IP-based solution, a proven scalable architecture GRX Root Tier 0/1 MMSC (A) 5,9 PLMN A 1,6 2,7 3 GRX 4,8 MMSC (B) PLMN B 1. MMSC queries local / for NAPTR record of e164enum.net. 2. Local / queries GRX root for NAPTR record of e164enum.net. and receives NS and A records of e164enum.net. 3. Local / queries Tier 0/1 for NAPTR record of e164enum.net. and receives NS and A records of e164enum.net. 4. Local / queries remote / for NAPTR record of of e164enum.net. and receives NAPTR records (mailto: @mms.mncxxx.mccxxx.gprs). 5. Local / returns NAPTR records to MMSC that retrieves the mailto URI. 6. MMSC queries local / for MX record of mms.mncxxx.mccxxx.gprs. 7. Local / queries GRX root for MX record of mms.mncxxx.mccxxx.gprs. and receives NS and A records of mncxxx.mccxxx.gprs. 8. Local / queries remote / for MX record of mms.mncxxx.mccxxx.gprs. and receives MX of mncxxx.mccxxx.gprs. and A records for the hosts in MX records 9. Local / returns MX and A records to MMSC 19 for Inter-Working IMS in GSM Community / e164enum.net. NAPTR RRs RFC 3263 process performed to locate SIP servers for OpB.3gppnetwork.org. tel: S-CSCF sip.opa. 3gppnetwork.org User=phone sip: I-CSCF/S-CSCF sip.opb. 3gppnetwork.org IP address =

11 Summary - Private / for GSM Operators At present, two suffixes are supported in GSMA GRX.gprs (used by mobile operators).grx (used by GRX carriers) Another suffix will be added soon to GRX for new services to avoid hitting the root servers in Internet by misconfigured nodes 3gppnetwork.org Another one for Infrastructure e164enum.net 21 Observations There is no common infrastructure for CDMA community. CDMA operator designated is necessary for all inter-working related services, which require secure and scalable mechanism for addressing resolution. Inter-working with GSM operators requires interface to GSM existing infrastructure, such as its GRX,, as well as. Inter-working on MMS, PoC, and IMS/MMD, etc. Operator is a proven mechanism for MNP. CRX for CDMA operators is deployed and in service. Introducing would be practical and beneficial to CDMA community CDG MMS Team is working with GSMNA MMS Project team to resolve the MMS Inter-working issues between CDMA and GSM operators in NA / is emerging as an important issue for CDG to consider CRX/GRX peering is also critical to exchange traffic 22 11

12 A Vision Harmonized IP exchange (IPX) Backbone All of them share the same private infrastructure that is separated from Internet and can exchange control- and user-plan traffic via IPX infrastructure (Peered IGRX/CRX) with one another GSM operators CDMA operators Fixed/NGN operators Cable operators Harmonized IPX (Interconnected IPXs with end-to-end QoS) Application providers Content providers VoIP SPs WLAN SPs 23 Questions? Please contact: Richard Xu, Aicent x529 (B) (M) James Yu, NeuStar (B) (M) 24 12