Download presentation
Presentation is loading. Please wait.
Published byStella Pierce Modified over 8 years ago
1
Header Compression for Communication exceed 6LoWPAN 20091029
2
outline Problem statement and analysis Solution 1-the existing technical Solution 2-Header Compression base on binding table
3
Problem statement and analysis(1/2) packet transportation within 6LoWPAN –Source and destination IPv6 addresses in adaptation layer header use MAC addresses, e.g. 7 octet. Reference to RFC4994 6LoWPAN nodes communicate to nodes outside –The source IPv6 address prefix, the prefix and interface identifier of destination IPv6 address would not be omitted, for a total 24 octet.
4
Problem statement and analysis(2/2) In the 6LoWPAN applications, more scenarios is the communication among nodes within and out of 6lowpan. The cost reduction is to be further addressed, in case a 6LoWPAN node sends a IPv6 package to an IP address outside.
5
Solution 1 twice-NAT FE80::1:1:1:1 FE80::2:2:2:2 FE80::3:3:3:3 402::0/128 202::234:89 www.huawei.com 1. Send a DNS request Q=www.huawei.com NAT table FE80::A:A:A:A=202::23 4:89 2.Gateway DNS request Q=www.huawei.com R=202::234:89 3.Router reply R=FE80::A:A:A:A 4.Connection request source IP: FE80::3:3:3:3 Dest IP: FE80::A:A:A:A FE80::1:1:1:1=402::1 FE80::2:2:2:2=402::2 FE80::3:3:3:3=402::3 5.Translation request source IP: 402::3 dest IP: 202::234:89 7.Translation reply source IP: FE80::A:A:A:A Dest IP: FE80::3:3:3:3 6.Connection reply source IP: 202::234:89 Dest IP: 402::3 Save 16 byte prefix when use 64-bit extended address The allocation of internal address to external equipment of 6loWPAN and management will be Complex. FE80::7:7:7:7 Reference to: IPv6 Global to Link-layer ADdress Translation for 6LoWPAN Overhead Reducing Zimmermann, A.; Sa Silva, J.; Sobral, J.B.M.; Boavida, F.;
6
Solution 2 The mechanism to use 16bits short address to identify 6LoWPAN nodes; A binding table with scheme of 16bit short address, PAN id, binding id, identifier of external node and binding expiration, maintained by edge router NOTE: information already stored in edge router. Edge gateway converts inner identifiers and outer identifiers when communication.
7
Solution 2 1. When a node A within the PAN communicate to nodes outside PAN , the packet is sent to the edge router with 16bits short address and identifier of destination (IP address or host name). 6LoWPAN edge router uses above binding table to maintain the connections with nodes out of 6LoWPAN. A static mapping or DNS query mechanism are used to establish the binding table FE80::1:1:1:1 FE80::2:2:2:2 FE80::3:3:3:3 402::0/128 202::234:89 www.huawei.com FE80::7:7:7:7 64bit MAC address 16bit short address PAN ID binding ID external device binding expiration
8
IPHC Encoding Extension 2. Node A uses16-bit short address and sends a request extension to DAM fields of LOWPAN_IPHC Encoding. 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ | 0 | 1 | 1 | TF |NH | HLIM |CID|SAC| SAM | M |DAC| DAM | +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ LOWPAN_IPHC Encoding DAM=10 no use of binding ID DAM=11 use of binding ID, In accordance with the indication to use binding ID, following 1 octet is to indicate binding ID 3. When node A using binding identifier, edge router fetches the binding table with 16-bit short address and binding ID, and encapsulates data packets sending to the corresponding node out of 6lowpan. If M=1 and DAC=1 00: 48 bits. 01: reserved. 10: reserved 11: reserved From Ietf-6lowpan-hc
9
binding table scheme(4/4) the maintenance of binding table as node move In the same subnet prefix within the different PAN FE80::1:1:1:1 FE80::2:2:2:2 FE80::3:3:3:3 402::0/128 202::234:89 www.huawei.com 402::1:0/128 FE80::9:9:9:9 FE80::f:f:f:f FE80::3:3:3:3 64bit MAC address 16bit short address PAN ID Binding ID external device binding period 3:3:3:3311202::234:89100 64bit MAC address 16bit short address PAN ID Binding ID external device binding period 3:3:3:3821202::234:89100
10
Compare of two solution headerMAC headeradaptation header fieldSource addrDest addrsource IPdest IP Twice-NAT3:3:3:3(64bi t) 7:7:7:7(64 bit) 0bitA:A:A:A(64bit) Binding- table 3(16bit)0(16bit)0bit FE80::1:1:1:1FE80::2:2:2:2 FE80::3:3:3:3 402::0/128 202::234:89 www.huawei.com FE80::7:7:7:7 Compare to solution 1,the Binding-table solution can reduce 160 bits. Phy headerMAC headerAdaptation headerIP payload
11
Consideration next steps Extension to LOWPAN_IPHC Encoding in page 8 is possible to define alternative methods.
12
Thanks!
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.