Network Mobility Across Private Domains Harish Viswanathan, S ampath Rangaraj an, S uman Das April, 2007
Mobile Broadband – new usage scenarios “ 3G Routers” appearing in the market Mobile broadband is evolving to provide Approved by S print, Verizon, Vodafone high data rates New services and usage models of wide INTERNET area wireless networks are emerging Further increase in data rates and EV-DO capacities of MBNs are planned for the future � UMB, LTE, WiMax DIR 450 EV- WiFi DO Router Wide area mobile broadband wireless enables from D-Link CIS CO 3G WWAN network mobility Router 3G Digi-Connect Kyocera 2 | Network Mobility | April 2007
Example S cenario I: Personal Area Networks in Transit Public Address Public Address Private Network Address Movement 3 | Network Mobility | April 2007
Example S cenario – II: Mobile Mesh – Rapidly Deployable Network • Network deployed where needed • Operating network INTERNET components move as Public Address a whole • Internet connectivity may not be there initially Private Address Domain Movement Movement 4 | Network Mobility | April 2007
Motivation Future networks are likely to be mobile themselves � Network itself will be portable � Example: Rapidly deployable networks for emergency application � Personal area networks between multiple devices move together or separately and j oin other networks � Connectivity to backbone network may not be available before network operation How do we provide services and seamless mobility management when network moves? � Evolutionary Approach: Achieve this goal with minimum changes to existing core infrastructure and protocols 5 | Network Mobility | April 2007
Mobility Management Aspects Treated Layer 3 (IP layer) mobility � Retain IP address � Be able to route to new location with existing IP address Layer 1 and Layer 2 mobility is handled in a network technology dependent manner S eamless connectivity depends on handoff times at Layers 1, 2, and 3 � Restarting/ handoff at Layer 1 and 2 typically faster with properly designed technology If Layer 1 and 2 handoff causes substantial interruption resulting in loss of service then seamless Layer 3 mobility may be irrelevant 6 | Network Mobility | April 2007
Typical S cenario Characteristics Local network of access points inter- connected by mesh or other point-to- Commercial multi-point network Wide Area Wireless Network One of the nodes, “ Gateway AP” , has connectivity to the Internet through a wide area access network Mobility S cenarios Gateway � Access terminals (AT) moving within the local network � ATs moving out of the local network � A portion of the local network (AP+ATs) moves and j oins another similar local network 7 | Network Mobility | April 2007
Mobility S cenario – AT moving out of local network New Configuration Initial Configuration Commercial Commercial Cellular Network Cellular Network NAT/Gateway NAT/Gateway NAT/Gateway NAT/Gateway Network B Network B Network A Network A 8 | Network Mobility | April 2007
Mobility S cenario – AP moving out of the local network Initial Configuration New Configuration Commercial Commercial Cellular Network Cellular Network Gateway Gateway Gateway Gateway Network B Network B Network A Network A 9 | Network Mobility | April 2007
Mobility S cenario 3 – Entire Private domain moving under another private domain Initial Configuration New Configuration Commercial Commercial Cellular Network Cellular Network NAT/Gateway NAT/Gateway NAT/Gateway Network B Network A 10 | Network Mobility | April 2007
Related Work: Network Mobility S olutions IETF NEMO (Network Mobility) working group has proposed a solution for network mobility � Assumes IPv6 prefix based global addressing � Assumes mobile node connected to the Internet is a mobile router � Based on Mobile IPv6 extensions � Incorporates suffix binding to reduce signaling � Applicable to IPv4 with public addresses only Main Idea � MRs registers network segments explicitly with the HA or known implicitly to the HA. Packets to these network segments received at the HA will be forwarded to the MR 11 | Network Mobility | April 2007
Key Components of the Network Service Provider Network Gateway Access Point (AP) Wide Area Wireless Network F-HA Access Point (AP) Access Terminal (AT) Local network Wide Area Access Provider Network Gateway AP Local Fixed Network Home Agent (F-HA) Network AP AT 12 | Network Mobility | April 2007
Direct Mobile IP S olution � Gateway AP acts as the foreign Service Provider agent for AT in standard Mobile IP Network � Public home address assigned to AT by F-HA through gateway using Wide Area Wireless Network F-HA Mobile IP � FA is itself mobile; Home address assigned to it by F-HA Disadvantages � Does not address mobility for calls that Gateway AP Local originated before infrastructure connectivity was Network available � Infrastructure needs to be aware of all nodes AP in local network � Tunneling overhead even in the absence of mobility AT � Local traffic has to be routed through Gateway AT even in the absence of mobility 13 | Network Mobility | April 2007
Mobility S olution with private addresses Co-locate Home Agent functionality for local network nodes at the Gateway node together with the NAT � When nodes move, because of private addressing packets will continue to have to be address translated for on-going connections to be maintained Directly tunnel packets from an AP to the Gateway AP to hide old private addresses in the new local network Route optimization whenever possible When Gateway AP itself moves under another Gateway AP then it is possible to route packets directly in the new local network 14 | Network Mobility | April 2007
Gateway AP Functions Router Personality Host Personality Co-located Local HA FA NAT Routing FA WAN LAN Interface Interface 15 | Network Mobility | April 2007
Example: Initial Configuration Access-Interface Link 192.168.1.1 135.222.104.1 Commercial 2 Mesh Interface-Link Cellular Network 3 192.168.15.5 192.168.15.1 192.168.1.1 135.222.104.1 4 3 4 Backhaul-Interface Links Gateway AP B Gateway AP A 135.22.108.10 135.222.104.1 2 5 5 Mesh Interface-Link 192.168.5.1 192.168.5.10 135.22.108.10 192.168.10.1 6 6 Access-Interface Link 1 135.22.108.10 192.168.10.1 16 | Network Mobility | April 2007
When Gateway AP A moves under Gateway AP B 1 Access-Interface Link 192.168.1.1 135.222.104.1 Commercial 2 Mesh Interface-Link Cellular Network 192.168.15.5 192.168.15.1 192.168.1.1 135.222.104.1 3 Mesh-Interface Link to NAT B NAT/Gateway 192.168.5.3 192.168.5.1 135.222.108.10 135.222.104.1 4 3 4 Mesh Interface-Link NAT/Gateway 192.168.5.1 192.168.5.10 135.22.108.10 192.168.10.1 2 5 5 Access-Interface Link 1 135.22.108.10 192.168.10.1 17 | Network Mobility | April 2007
When only AP moves Commercial Cellular Network 3 HA+NAT Gateway AP B FA 4 Gateway AP A 2 5 1 18 | Network Mobility | April 2007
S ummary Network mobility is likely to become increasingly common with advent of mobile broadband wireless Private addressing and NAT may continue to be in use in some scenarios Maintaining calls when networks move can be addressed by locating HA in the local network together with the NAT S ignaling optimizations similar to IETF NEMO solution can be incorporated 19 | Network Mobility | April 2007
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