|Title of Invention||
A METHOD FOR FAST ROUTER ADVERTISMENT
|Abstract||This invention is related to Detecting Network Attachment in particular Fast RA mechanisms. This is applicable for DNA routers. This method decreases the time taken for DNA hosts to receive RA after sending RS. More particularly the present invention relates to a method forality of routers and plurality of hosts, coprising the steps of maintainignt he priorities and addresses of all the other routers in the link by the routers, and calculating the ranking among the routers by each router when RS is received from a host.|
|Full Text||FORM 2
THE PATENTS ACT, 1970
[39 of 1970]
THE PATENTS RULES, 2003
(Section 10; Rule 13)
A METHOD FOR FAST ROUTER ADVERTISEMENT
SAMSUNG INDIA SOFTWARE OPERATIONS PVT. LTD.,
BAGMANE LAKEVIEW, BLOCK 'B',
No. 66/1, BAGMANE TECH PARK,
C V RAMAN NAGAR,
BANGALORE - 560093
A wholly owned subsidiary
of Samsung Electronics Company Limited, Korea,
an Indian Company
The following Specification particularly describes the invention and the
manner in which it is to be performed
FIELD OF THE INVENTION
The present invention, in general relates to the field of communication over networks. This invention further relates to Detecting Network Attachment (DNA) in particular Fast Router Advertisement (RA) mechanisms. This is applicable to DNA routers. This method decreases the time taken for DNA hosts to receive RA after sending Router Solicitation (RS). More particularly the present invention relates to a method for fast router advertisement.
DESCRIPTION OF RELATED ART
i) DNAv6 Fast RA mechanism: DNAv6 avoids the delay in sending router advertisement by using a mechanism to ensure that two routers will not respond at exactly the same time while allowing one of the routers on the link to respond immediately. The mechanism is based on the routers on the link determining, the link-local addresses of all the other routers on the link. Routers calculate ranking among them based on the routers' addresses and host address to send the router advertisement in response to router solicitation. RA will be scheduled as per the ranking.
ii) Fast Router Discovery with L2 support: This proposes a quick RA acquisition mechanism with the help of a link layer entity, point of attachment. This proposes two methods namely RA Triggering and RA Proxying. In RA Triggering, point of attachment triggers access router to send RA. In RA Proxying, point of attachment itself sends RA. PoA can store the RA advertised by the routers or RA can be manually configured.
Limitations of DNAv6 Fast RA mechanism
i) Since ranking among the routers will be same for a given host address, load distribution may not be even.
ii) Priority is not considered among the routers
iii) More computation is required, since it uses SHA-1 value of the address
Limitations of Fast Router Discovery with L2 support
i) Security problems can be there because of proxying.
ii) In RA Proxying, the router advertisement that host receives may be stale.
iii) Since random delays are not used, some times this method may cause congestion.
SUMMARY OF THE INVENTION
This invention is related to sending router advertisement quickly by the access routers, so that hosts can detect the network attachment quickly. This invention proposes a way to calculate the ranking among the routers to send RA quickly and effectively. The invention uses router addresses, host address, current time and priority of the router to calculate ranking among the routers. Routers will send the RAs in response to RSS as per the rankings.
Accordingly, this invention explains a method for fast router advertisement (RA) in a communication system comprising plurality of routers and plurality of hosts, comprising the steps of:
i) maintaining the priorities and addresses of all the other routers in the link by the routers; and
ii) calculating the ranking among the routers by each router when RS is received from a host.
The said method involves exchange of RS, RA between the hosts and routers quickly without collision and congestion. The said method involves avoiding the delay when host sends RS with DNA option.
Router calculating XOR of routers addresses, host address and time after receiving RS. Sorting the routers in the increasing order based on the XOR calculation. The method further comprises setting all the priorities to 1 if priorities are not set. Further the method comprises reordering the routers based on the priorities if the priority of any router is greater than 1. The said method involves moving the router priority p-1 positions up, if the priority of the router in that position is less than router priority p, for all the routers and for all the priorities starting from highest priority to lowest priority.
These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 shows a possible scenario where this invented method is applicable.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail.
The object of the invention can be summarized as follows: Future wireless networks will rely on packet switching technologies and will be entirely based on the IP protocol suite, both in the wireless and wired parts of the network. Since IP
was not designed with mobility in mind, there are several problems that need to be solved before all-IP wireless networks are deployed. When a mobile node moves inside the network from one subnet to another subnet, it needs to configure new IP address. Before configuring new IP address, it needs to identify if subnet (i.e., layer 3 connectivity) is changed or not.
When a mobile node detects that its Layer 2 is changed, it needs to check if subnet is changed or not. Mobile node needs to detect the subnet change as soon as possible, so that the handoff delay can be reduced. Mobile node can exchange router solicitation and router advertisement to identify the link change. As per the neighbor discovery procedures, routers will respond after a random delay to avoid collision and congestion. This delay may not be acceptable some real time applications such as Voice over IP.
The primary object of this invention is to enable a host to receive RA quickly after sending RS thereby the host can detect the link change and configure routing and address information.
The operation of the invention is as follows:
Figure 1 shows a possible scenario where this invented method is applicable. PAP and PAR are the access point and access router with which MN is previously associated with. NAP and NAR are the access point and access router with which MN is currently associated. MN will perform the procedures described in this invention to detect if its Iayer3 connection is changed or not after attaching to NAP.
To detect the change in the network attachment, host needs to have an identifier which identifies the link and a mechanism to receive that identifier quickly. Router Solicitation and Router Advertisements can be used to receive the identifier. This RS, RA exchange mechanism proposed in the neighbor discovery procedures incurs some delay to avoid collision and congestion.
This invention proposes a method to exchange RS, RA between the hosts and routers quickly without causing collision and congestion.
The operation of the proposed invention is described herein:
1)When host sends RS with DNA option, to avoid the delay due to standard NDP procedures,
i)DNA routers can calculate the ranking among the routers (as specified in step 4,5 and 6)
ii)Send unicast RAs with a configurable unicast advertisement interval (default value = 20 milli seconds)
2)Routers will synchronize their time (may be using network time protocol or some other mechanisms)
3)Routers are given priorities. These priorities can be given based on:
i)Load routers can handle.
ii)No. of prefixes advertised by the routers.
iii)may be some other factors also
All the routers need to know other routers priorities. If the routers are not configured with priorities, they can set default value to 1.
4)Routers calculate the XOR of each DNA router address, Host address and Time after receiving RS. (Only least 64 bits of the 128 bit addresses needs to be considered)
5)The result of these XOR operations is sorted from lowest to highest. If two or more values are equal, then they are sorted in the order of their (routers) addresses.
6) Now routers will run the following algorithm to reorder the rankings based on priority. For each priority p from the highest priority to the lowest priority do the following
i) For each router with rank r from the 0 to maximum do the following: If the router priority is p and if the (r-(p-1)) th router priority (if any) is less than p, put this router at (r-(p-1)) th position and shift the routers from (r-(p-1)) to maximum one rank down.
i) For a given host, rankings of routers will not be same unlike in the [DNAv6] mechanism.
ii) Complexity in calculating rankings is less.
iii) This method takes care of congestion problems.
iv) This method never gives the stale information.
v) Since this method considers priorities, Load can be distributed based on what the routers can handle
vi) By giving priorities to the routers with most number of prefixes, some of the synchronization problems with DNA methods can be solved.
It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is
to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
GLOSSARY OF TERMS AND DEFINITIONS THEREOF
AP - Access Point
AR - Access Router
DNA - Detecting Network Attachment
MN - Mobile Node
NAP - New Access Point
NAR - New Access Router
NDP - Neighbor Discovery Protocol
PAP - Previous Access Point
PAR - Previous Access Router
PoA - Point of Attachment
RA - Router Advertisement
RS - Router Solicitation
Kempf, et al. Detecting Network Attachment in IPv6 Networks (DNAv6), draft-pentland- dna-protocol-01.txt, July 2005
Choi & Shin Detecting Network Attachment in IPv6 Networks (DNAv6), draft-jinchoi-dna-frd-01.txt,July,2005
|Indian Patent Application Number||593/CHE/2006|
|PG Journal Number||27/2013|
|Date of Filing||31-Mar-2006|
|Name of Patentee||SAMSUNG INDIA SOFTWARE OPERATIONS PRIVATE LIMITED|
|Applicant Address||EMPLOYED AT SAMSUNG INDIA SOFTWARE OPERATIONS PVT. LTD C V RAMAN NAGAR, BYRASANDRA, BANGALORE 560 093 KARNATAKA|
|PCT International Classification Number||G04M 3/00|
|PCT International Application Number||N/A|
|PCT International Filing date|