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Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We’re making these slides freely available to all (faculty, students, readers). They’re in PowerPoint form so you see the animations; and can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: If you use these slides (e.g., in a class) that you mention their source (after all, we’d like people to use our book!) If you post any slides on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material. Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Thanks and enjoy! JFK/KWR All material copyright 1996-2012 J.F Kurose and K.W. Ross, All Rights Reserved Wireless, Mobile Networks 6-1 Chapter 6 outline 6.1 Introduction Mobility Wireless 6.5 Principles: addressing and routing to mobile users 6.6 Mobile IP 6.7 Handling mobility in cellular networks 6.8 Mobility and higher-layer protocols 6.2 Wireless links, characteristics CDMA 6.3 IEEE 802.11 wireless LANs (“Wi-Fi”) 6.4 Cellular Internet Access architecture standards (e.g., GSM) 6.9 Summary Wireless, Mobile Networks 6-2 Ch. 6: Wireless and Mobile Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers (>5-to-1)! 41% of homes in U.S. do not have a land-line telephone (2014) # wireless Internet-connected devices now exceeds # wire line Internet-connected devices laptops, Internet-enabled phones promise anytime untethered Internet access two important (but different) challenges wireless connectivity: communication over wireless link mobility: handling the mobile user who changes point of attachment to network Wireless, Mobile Networks 6-3 Elements of a wireless network network infrastructure Wireless, Mobile Networks 6-4 Elements of a wireless network wireless hosts network infrastructure laptop, smartphone, tablet run applications may be stationary (nonmobile) or mobile wireless does not always mean mobility Wireless, Mobile Networks 6-5 Elements of a wireless network base station network infrastructure typically connected to wired network relay - responsible for sending packets between wired network and wireless host(s) in its “area” e.g., cell towers, 802.11 access points Wireless, Mobile Networks 6-6 Elements of a wireless network wireless link network infrastructure typically used to connect mobile(s) to base station also used as backbone link multiple access protocol coordinates link access various data rates & transmission ranges Wireless, Mobile Networks 6-7 Characteristics of selected wireless links Data rate (Mbps) 200 802.11n 54 802.11a,g 5-11 802.11b 4G: LTE 802.11a, g point-to-point Enhanced 3G: HSPA 4 1 802.15 .384 2.5G: UMTS/WCDMA, CDMA2000 .056 2G: IS-95, CDMA, GSM Indoor Outdoor 10-30m 50-200m Mid-range outdoor Long-range outdoor 200m – 4 Km 5Km – 20 Km Wireless, Mobile Networks 6-8 Elements of a wireless network infrastructure mode network infrastructure base station connects mobiles into wired network handoff: mobile changes the base station that is providing its connection to the wired network Wireless, Mobile Networks 6-9 Elements of a wireless network ad hoc mode no base stations nodes can only transmit to other nodes within link coverage nodes organize themselves into a network: route among themselves Wireless, Mobile Networks 6-10 Wireless network taxonomy single hop infrastructure (e.g., APs) no infrastructure host connects to base station (WiFi, 3G cellular) which connects to larger Internet no base station, no connection to larger Internet (Bluetooth, WiFi ad hoc nets) multiple hops host may have to relay through several wireless nodes to connect to larger Internet: mesh net no base station, no connection to larger Internet. May have to relay to reach other a given wireless node MANET, VANET Wireless, Mobile Networks 6-11 Chapter 6 outline 6.1 Introduction Mobility Wireless 6.5 Principles: addressing and routing to mobile users 6.6 Mobile IP 6.7 Handling mobility in cellular networks 6.8 Mobility and higher-layer protocols 6.2 Wireless links, characteristics and technical challenges CDMA 6.3 IEEE 802.11 wireless LANs (“Wi-Fi”) 6.4 Cellular Internet Access architecture standards (e.g., GSM) 6.9 Summary Wireless, Mobile Networks 6-12 Wireless Link Characteristics (1) important differences from wired link …. decreased signal strength: radio signal attenuates as it propagates through matter (path loss) interference from other sources: standardized (unlicensed) wireless network frequencies (e.g., 2.4 GHz) shared by other devices (e.g., portable phone, EGDOs); devices (motors) interfere as well multipath propagation: radio signal reflects off objects ground, arriving at destination at slightly different times, phases & intensities (signal diffusion) …. make communication across wireless link (even pointto-point) much more “difficult” than over a wired link Wireless, Mobile Networks 6-13 Wireless Link Characteristics (2) SNR: signal-to-noise ratio 10-1 larger SNR – easier to extract signal from noise (a “good thing”) SNR versus BER tradeoffs for given physical layer modulation: increase power -> increase SNR->decrease BER for given SNR: choose physical layer that meets BER requirement, giving highest throughput • SNR may change with mobility: dynamically adapt physical layer (modulation technique, rate) 10-3 BER 10-2 10-4 10-5 10-6 10-7 10 20 30 40 SNR(dB) QAM256 (8 Mbps) QAM16 (4 Mbps) BPSK (1 Mbps) Wireless, Mobile Networks 6-14 Wireless network characteristics Multiple wireless senders and receivers create additional problems (beyond multiple access): B A C C B C’s signal strength A’s signal strength A Hidden terminal problem B, A hear each other B, C hear each other A, C can not hear each other means A, C unaware of their interference at B space Signal attenuation: B, A hear each other B, C hear each other A, C can not hear each other interfering at B Wireless, Mobile Networks 6-15 Code Division Multiple Access (CDMA) unique “code” assigned to each user; i.e., code set partitioning all users share same frequency, but each user has own “chipping” sequence (i.e., code) to encode data allows multiple users to coexist and transmit simultaneously in the same physical media with minimal interference (if codes are “pairwise orthogonal”) encoded signal = (original data) X (chipping sequence) decoding: inner-product of encoded signal and chipping sequence Wireless, Mobile Networks 6-16 CDMA encode/decode sender d0 = 1 data bits code Zi,m= di.cm -1 -1 -1 1 -1 1 1 1 -1 -1 -1 slot 1 -1 slot 1 channel output 1 -1 1 1 1 1 1 1 1 d1 = -1 1 1 1 channel output Zi,m -1 -1 -1 slot 0 1 -1 -1 -1 -1 slot 0 channel output M Di = S Zi,m.cm m=1 received input code receiver 1 1 1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 -1 1 1 1 -1 -1 -1 slot 1 M 1 1 -1 -1 -1 -1 slot 0 d0 = 1 d1 = -1 slot 1 channel output slot 0 channel output Wireless, Mobile Networks 6-17 CDMA: two-sender interference Sender 1 channel sums together transmissions by sender 1 and 2 Sender 2 using same code as sender 1, receiver recovers sender 1’s original data from summed channel data! Wireless, Mobile Networks 6-18 Chapter 6 outline 6.1 Introduction Mobility Wireless 6.5 Principles: addressing and routing to mobile users 6.6 Mobile IP 6.7 Handling mobility in cellular networks 6.8 Mobility and higher-layer protocols 6.2 Wireless links, characteristics CDMA 6.3 IEEE 802.11 wireless LANs (“Wi-Fi”) 6.4 Cellular Internet Access architecture standards (e.g., GSM) 6.9 Summary Wireless, Mobile Networks 6-19 IEEE 802.11 Wireless LAN 802.11a 5-6 GHz range up to 54 Mbps 802.11b 2.4-2.5 GHz up to 11 Mbps 802.11g 2.4-2.5 GHz range up to 54 Mbps 802.11n: Multiple antennae: MIMO • 4 spatial streams 2.4 or 5 GHz range up to 200 Mbps 802.11 ac (MIMO) Multiple antennae: MIMO • 8 spatial streams 5 GHz range up to 867 Mbps (theoretical to 1.37 Gbps) limited range, but… Wireless, Mobile Networks 6-20 IEEE 802.11 Wireless LAN Modulation/multiplexing 802.11b: direct sequence spread spectrum (DSSS) in physical layer 80211a/g: orthogonal frequency division multiplexing (OFDM) 802.11n: spatial division multiplexing (SDM) 802.11ac: spatial division multiplexing (SDM) with QAM 256 per channel, and beamforming all use CSMA/CA for multiple access all support infrastructure and ad-hoc network operation Wireless, Mobile Networks 6-21 IEEE 802.11 Wireless LAN Physical layer modulation/multiplexing DSSS modulation (802.11b) CDMA-like physical transmission with 8-bit chipping sequence 14 overlapping frequency bands (11 useable channels) OFDM modulation (802.11a/g) FDM-like modulation with all frequencies pairwise-orthogonal Reverts to DSSS (11 MBPS) for 802.11b compatibility SDM modulation (802.11n & 802.11ac) Complex OFDM schema using QAM modulation across 4 or 8 spatial streams with multiple antennae and frame aggregation Wireless, Mobile Networks 6-22 802.11 LAN architecture Internet Wireless Host communicates with base station base station = access point (AP) hub, switch or router BSS 1 Basic Service Set (BSS) (aka a WiFi “cell”) in infrastructure mode contains: wireless host(s) access point (AP): base station (ad hoc mode has hosts only) BSS 2 Wireless, Mobile Networks 6-23 802.11: Channels, association 802.11b/g: 2.401GHz-2.485GHz spectrum divided into 11 channels at different frequencies wireless network admin chooses frequency for AP interference possible: channel can be same as that used by a neighboring AP! SDM used in 802.11n & ac with 4 & 8 MIMO streams reduces cross channel interference host: must associate with an AP scans channels, listening for beacon frames containing AP’s name (SSID) and MAC address selects AP to associate with may perform authentication [Chapter 8] will typically run DHCP to get IP address in AP’s subnet (note: AP device may also serve as local router) Wireless, Mobile Networks 6-24 802.11: association via passive/ active scanning BBS 1 BBS 1 BBS 2 BBS 2 1 AP 1 1 1 2 AP 2 AP 1 2 3 2 3 AP 2 4 H1 H1 passive scanning (typical): active scanning: (1) beacon frames sent from APs (2) association Request frame sent: H1 to selected AP (3) association Response frame sent from selected AP to H1 (1) Probe Request frame broadcast from H1 (2) Probe Response frames sent from APs (3) Association Request frame sent: H1 to selected AP (4) Association Response frame sent from selected AP to H1 Wireless, Mobile Networks 6-25 IEEE 802.11: multiple access avoid collisions: 2+ nodes transmitting at same time 802.11: CSMA - sense before transmitting don’t collide with ongoing transmission by another node 802.11: does not use collision detection! difficult/expensive to receive (sense collisions) when transmitting due to weak received signals (fading) can’t sense all collisions in any case: hidden terminal, fading goal: avoid collisions: CSMA/CA(Collision Avoidance) B A C C A B C’s signal strength A’s signal strength space Wireless, Mobile Networks 6-26 IEEE 802.11 MAC Timing duration depends on MAC load type duration depends on network condition MAC frame: Control, management , data + headers (size depends on frame load and type) Reference: W. Stallings: Data and Computer Communications, 7th ed DIFS: Distributed Inter-Frame Space (minimum delay for asynchronous frame access) SIFS: Short Inter-Frame Space (minimum timing for high priority frame access as ACK, CTS, MSDU…) 10 IEEE 802.11 MAC Protocol: CSMA 802.11 sender 1. if sense channel idle for DIFS then transmit entire frame (no CD) 2. if sense channel busy then start random back-off time timer counts down while channel idle transmit when timer expires if no ACK, increase random back-off interval, repeat 2 802.11 receiver - if frame received OK sender receiver DIFS data SIFS ACK return ACK after SIFS (ACK needed due to hidden terminal problem) Wireless, Mobile Networks 6-28 Avoiding collisions (CSMA/CA) concept: allow a sender to “reserve” channel rather than random access of data frames: avoid collisions of long data frames sender first transmits small request-to-send (RTS) packets to AP using CSMA RTSs may still collide with each other (but they’re short) AP broadcasts clear-to-send CTS in response to RTS CTS heard by all nodes sender transmits data frame other stations defer transmissions avoid data frame collisions completely using small reservation packets! Wireless, Mobile Networks 6-29 Collision Avoidance: RTS-CTS exchange A B AP reservation collision DATA (A) defer time Wireless, Mobile Networks 6-30 802.11 frame: addressing 2 2 6 6 6 frame address address address duration control 1 2 3 Address 1: MAC address of wireless host or AP to receive this frame (receiver) 2 6 seq address 4 control 0 - 2312 4 payload CRC Address 4: used only in ad hoc mode Address 3: MAC address of router interface to which AP is attached Address 2: MAC address of wireless host or AP transmitting this frame (sender) Wireless, Mobile Networks 6-31 802.11 frame: addressing Internet R1 router H1 R1 MAC addr H1 MAC addr dest. address source address 802.3 frame AP MAC addr H1 MAC addr R1 MAC addr address 1 address 2 address 3 802.11 frame Wireless, Mobile Networks 6-32 802.11 frame: more frame seq # (for RDT) duration of reserved transmission time (RTS/CTS) 2 2 6 6 6 frame address address address duration control 1 2 3 2 Protocol version 2 4 1 Type Subtype To AP 6 2 1 seq address 4 control 1 From More AP frag 1 Retry 1 0 - 2312 4 payload CRC 1 Power More mgt data 1 1 WEP Rsvd frame type (RTS, CTS, ACK, data) Wireless, Mobile Networks 6-33 802.11: mobility within same subnet H1 remains in same IP subnet: IP address can remain same switch: which AP is associated with H1? self-learning (Ch. 5): switch will see frame from H1 and “remember” which switch port can be used to reach H1 BBS 1 H1 BBS 2 Wireless, Mobile Networks 6-34 802.11: advanced capabilities Rate adaptation base station, mobile dynamically change transmission rate (physical layer modulation technique) as mobile moves, SNR varies QAM256 (8 Mbps) QAM16 (4 Mbps) BPSK (1 Mbps) operating point 10-2 10-3 BER 10-1 10-4 10-5 10-6 10-7 10 20 30 SNR(dB) 40 1. SNR decreases, BER increase as node moves away from base station 2. When BER becomes too high, switch to lower transmission rate but with lower BER Wireless, Mobile Networks 6-35 802.11: advanced capabilities power management node-to-AP: “I am going to sleep until next beacon frame” AP knows not to transmit frames to this node node wakes up before next beacon frame beacon frame: contains list of mobiles with APto-mobile frames waiting to be sent node will stay awake if AP-to-mobile frames to be sent; otherwise sleep again until next beacon frame Wireless, Mobile Networks 6-36 802.15.1: personal area network less than 10 m diameter replacement for cables (mouse, keyboard, headphones) ad hoc: no infrastructure master/slaves: slaves request permission to send (to master) master grants requests 802.15.1: evolved from Bluetooth specification 2.4-2.5 GHz radio band TDM, 625µsec channels FHSS, up to 4 Mbps P S P radius of coverage M S P S P M Master device S Slave device P Parked device (inactive) Wireless, Mobile Networks 6-37 Chapter 6 outline 6.1 Introduction Wireless 6.2 Wireless links, characteristics CDMA 6.3 IEEE 802.11 wireless LANs (“Wi-Fi”) 6.4 Cellular Internet access architecture standards (e.g., GSM) Mobility 6.5 Principles: addressing and routing to mobile users 6.6 Mobile IP 6.7 Handling mobility in cellular networks 6.8 Mobility and higher-layer protocols 6.9 Summary Wireless, Mobile Networks 6-38 Components of cellular network architecture MSC connects cells to wired tel. net. manages call setup (more later!) handles mobility (more later!) cell covers geographical region base station (BS) analogous to 802.11 AP mobile users attach to network through BS air-interface: physical and link layer protocol between mobile and BS Mobile Switching Center Public telephone network Mobile Switching Center wired network GSM: Global System for Mobile Communications Wireless, Mobile Networks 6-39 Cellular networks: the first hop Two primary techniques for sharing mobile-to-BS radio spectrum combined FDMA/TDMA: divide spectrum in frequency channels, divide each channel into time slots (2G) CDMA: code division multiple access (3G – used in addition to FDMA/TDMA) frequency DS-WCDMA time slots bands 4G and variants: more later Wireless, Mobile Networks 6-40 2G (voice) network architecture Base station system (BSS) MSC BTS G BSC Public telephone network Gateway MSC Legend Base transceiver station (BTS) Base station controller (BSC) Mobile Switching Center (MSC) Mobile subscribers Wireless, Mobile Networks 6-41 3G (voice+data) network architecture MSC G radio network controller Gateway MSC G SGSN Key insight: new cellular data network operates in parallel (except at edge) with existing cellular voice network voice network unchanged in core data network operates in parallel Public telephone network Public Internet GGSN Serving GPRS Support Node (SGSN) Gateway GPRS Support Node (GGSN) Wireless, Mobile Networks 6-42 3G (voice+data) network architecture MSC G radio network controller Public telephone network Gateway MSC G SGSN Public Internet GGSN radio interface (WCDMA, HSPA) radio access network Universal Terrestrial Radio Access Network (UTRAN) core network General Packet Radio Service (GPRS) Core Network public Internet Wireless, Mobile Networks 6-43 Evolution to 4G Promises advanced features and data rates of 100s of Mbps Evolved Packet Core (EPC) unifies circuit-switched cellular voice and packet-switched data networks into “all-IP” approach (e.g., packetized voice and data) can support 2G and 3G access networks Long-Term Evolution (LTE) Radio Network radio network utilizes ODFM in combination with FDMA/TDMA for downstream data each active node allocated one or more 0.5ms time slots in one or more frequency bands dynamic slot allocation/reallocation and modulation schema WiMAX evolving 802.16 standard Wireless, Mobile Networks 6-44 Chapter 6 outline 6.1 Introduction Wireless 6.2 Wireless links, characteristics CDMA 6.3 IEEE 802.11 wireless LANs (“Wi-Fi”) 6.4 Cellular Internet Access architecture standards (e.g., GSM) Mobility 6.5 Principles: addressing and routing to mobile users 6.6 Mobile IP 6.7 Handling mobility in cellular networks 6.8 Mobility and higher-layer protocols 6.9 Summary Wireless, Mobile Networks 6-45 What is mobility? spectrum of mobility, from the network perspective: no mobility mobile wireless user, using same access point high mobility mobile user, connecting/ disconnecting from network using DHCP. mobile user, passing through multiple access points while maintaining ongoing connections (like cell phone) Wireless, Mobile Networks 6-46 Mobility: vocabulary home network: permanent “home” of mobile (e.g., 128.119.40/24) home agent: entity that will perform mobility functions on behalf of mobile, when mobile is remote wide area network permanent address: address in home network, can always be used to reach mobile (e.g., 128.119.40.186) Wireless, Mobile Networks 6-47 Mobility: more vocabulary permanent address: remains constant (e.g., 128.119.40.186) visited network: network in which mobile currently resides (e.g., 79.129.13/24) care-of-address: address in visited network. (e.g., 79,129.13.2) wide area network correspondent: wants to communicate with mobile foreign agent: entity in visited network that performs mobility functions on behalf of mobile. Wireless, Mobile Networks 6-48 How do you contact a mobile friend: Consider friend frequently changing addresses, how do you find her? I wonder where Alice moved to? search all phone books? call her parents? expect her to let you know where he/she is? Wireless, Mobile Networks 6-49 Mobility: approaches let routing handle it: routers advertise permanent address of mobile-nodes-in-residence via usual routing table exchange. routing tables indicate where each mobile located no changes to end-systems let end-systems handle it: indirect routing: communication from correspondent to mobile goes through home agent, then forwarded to remote direct routing: correspondent gets foreign address of mobile, sends directly to mobile Wireless, Mobile Networks 6-50 Mobility: approaches let routing handle it: routers advertise permanent address of not via usual routing table exchange. mobile-nodes-in-residence scalable routing tables indicate where each mobile located to millions of no changes to end-systems mobiles let end-systems handle it: indirect routing: communication from correspondent to mobile goes through home agent, then forwarded to remote direct routing: correspondent gets foreign address of mobile, sends directly to mobile Wireless, Mobile Networks 6-51 Mobility: registration visited network home network 2 1 wide area network foreign agent contacts home agent home: “this mobile is resident in my network” mobile contacts foreign agent on entering visited network end result: foreign agent knows about mobile home agent knows location of mobile Wireless, Mobile Networks 6-52 Mobility via indirect routing home agent intercepts packets, forwards (via tunneling) to foreign agent foreign agent receives packets, forwards to mobile visited network home network 3 1 correspondent addresses packets using home address of mobile wide area network 2 4 mobile replies directly to correspondent Wireless, Mobile Networks 6-53 Indirect Routing: comments mobile uses two addresses: permanent address: used by correspondent (hence mobile location is transparent to correspondent) care-of-address: used by home agent to forward datagrams to mobile foreign agent functions may be done by mobile itself triangle routing: correspondent-home-networkmobile inefficient when correspondent, mobile are in same network Wireless, Mobile Networks 6-54 Indirect routing: moving between networks suppose mobile user moves to another network registers with new foreign agent new foreign agent registers with home agent home agent update care-of-address for mobile packets continue to be forwarded to mobile (but with new care-of-address) mobility, changing foreign networks transparent: on going connections can be maintained! Wireless, Mobile Networks 6-55 Mobility via direct routing correspondent forwards to foreign agent foreign agent receives packets, forwards to mobile visited network home network 3 1 correspondent requests, receives foreign address of mobile 2 4 mobile replies directly to correspondent Wireless, Mobile Networks 6-56 Mobility via direct routing: comments overcome triangle routing problem non-transparent to correspondent: correspondent must get care-of-address from home agent what if mobile changes visited network? 3 1 2 4 Wireless, Mobile Networks 6-57 Accommodating mobility with direct routing anchor foreign agent: FA in first visited network data always routed first to anchor FA when mobile moves: new FA arranges to have data forwarded from old FA (chaining) foreign net visited at session start wide area network anchor foreign agent 1 2 4 5 correspondent agent correspondent 3 new foreign agent new foreign network Wireless, Mobile Networks 6-58 Chapter 6 outline 6.1 Introduction Wireless 6.2 Wireless links, characteristics CDMA 6.3 IEEE 802.11 wireless LANs (“Wi-Fi”) 6.4 Cellular Internet Access architecture standards (e.g., GSM) Mobility 6.5 Principles: addressing and routing to mobile users 6.6 Mobile IP 6.7 Handling mobility in cellular networks 6.8 Mobility and higher-layer protocols 6.9 Summary Wireless, Mobile Networks 6-59 Mobile IP RFC 5944 (November 2010) has many features we’ve seen: home agents, foreign agents, foreign-agent registration, care-of-addresses, encapsulation (tunneling: packetwithin-a-packet) three components to standard: agent discovery registration with home agent indirect routing of datagrams Wireless, Mobile Networks 6-60 Mobile IP RFC 5944 Protocol Requirements A mobile node must be able to communicate with other nodes after changing its link-layer point of attachment to the Internet, yet without changing its IP address. A mobile node must be able to communicate with other nodes that do not implement these mobility functions. No protocol enhancements are required in hosts or routers that are not acting as any of the new architectural entities introduced in this RFC. All messages used to update another node as to the location of a mobile node must be authenticated in order to protect against remote redirection attacks. Wireless, Mobile Networks 6-61 Mobile IP: indirect routing foreign-agent-to-mobile packet packet sent by home agent to foreign agent: a packet within a packet dest: 79.129.13.2 dest: 128.119.40.186 dest: 128.119.40.186 Permanent address: 128.119.40.186 dest: 128.119.40.186 Care-of address: 79.129.13.2 packet sent by correspondent Wireless, Mobile Networks 6-62 Mobile IP: agent discovery agent advertisement: foreign/home agents advertise service by broadcasting ICMP messages (typefield = 9) type = 9 24 checksum =9 code = 0 =9 H,F bits: home and/or foreign agent R bit: registration required 16 8 0 standard ICMP fields router address type = 16 length registration lifetime sequence # RBHFMGV bits reserved 1 or more care-ofaddresses mobility agent advertisement extension Wireless, Mobile Networks 6-63 Mobile IP: registration example home agent HA: 128.119.40.7 foreign agent COA: 79.129.13.2 mobile agent MA: 128.119.40.186 (Also: agent solicitation via ICMP Type 10 message) ICMP agent adv. COA: 79.129.13.2 …. registration req. COA: 79.129.13.2 HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 9999 identification: 714 encapsulation format …. registration reply HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 4999 Identification: 714 encapsulation format …. registration req. COA: 79.129.13.2 HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 9999 identification:714 …. registration reply HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 4999 Identification: 714 …. time Internet visited network: 79.129.13/24 Wireless, Mobile Networks 6-64