Wireless switch network architecture implementing layer 3 mobility domains
Techniques and technologies are provided in which wireless switches, each supporting their own subnet, are configured as part of a mobility domain. Each wireless switch in the mobility domain can discover other wireless switches in the mobility domain upon joining the network, and establish a peering session with each of the other switches within the mobility domain. This can involve establishing a data tunnel, which operates according to GRE-over-IP, and a control connection between each pair of the wireless switches in the mobility domain. Each data tunnel carries complete Layer-2 (L2) packets between the first wireless switch and the second wireless switch. Each L2 packet comprises L2 header information (e.g., a VLAN identifier), and is made available at the destination wireless switch of the data tunnel. Each control connection comprises a peering session over Internet Protocol (IP) which operates according to the transmission control protocol (TCP). Each control connection is configured to transfer wireless client device mobility related control plane information between the first wireless switch and the second wireless switch. This architecture can allow a wireless client device to retain its layer 3 (L3) address when the wireless client device roams between wireless switches (e.g., the first wireless switch and the second wireless switch) which are part of the first mobility domain. As such, the wireless client device can maintains network layer connectivity when it roams within the first mobility domain.
1. A network, comprising:
a first wireless switch which supports a first subnet, wherein the first wireless switch is configured as part of a first mobility domain;
a second wireless switch which supports a second subnet, wherein the second wireless switch is configured as part of the first mobility domain, wherein the first wireless switch and the second wireless switch communicate with each other over a control connection and a data tunnel to exchange complete Layer-2 (L2) packets between the first wireless switch and the second wireless switch;
a peering mechanism in the first mobility domain configured to establish a peering session that transfers wireless client device mobility-related control plane information over the control connection between the first wireless switch and the second wireless switch, and
a wireless client device having a first layer 3 (L3) address, wherein the wireless client device retains its first L3 address when roaming between the first wireless switch and the second wireless switch.
2. The network according to claim 1 , wherein the wireless client device maintains network layer connectivity when the wireless client device roams within the first mobility domain from the first wireless switch to the second wireless switch.
3. The network according to claim 1 , wherein the first wireless switch and the second wireless switch are configured with a common mobility domain string identifier (MDSI) which identifies the first wireless switch and the second wireless switch as being part of the first mobility domain.
4. The network according to claim 3 , further comprising:
a third wireless switch which supports a third subnet, wherein the third wireless switch is configured as part of a second mobility domain.
5. The network according to claim 4 , wherein the wireless client device loses network layer connectivity when the wireless client device roams from either the first wireless switch or the second wireless switch to the third wireless switch.
6. The network according to claim 4 , wherein the wireless client device acquires a new L3 address to regain network layer connectivity when the wireless client device roams from either the first wireless switch or the second wireless switch to the third wireless switch.
7. The network according to claim 6 , wherein first layer 3 (L3) address comprises a first Internet Protocol (IP) address, and wherein new layer 3 (L3) address comprises a new Internet Protocol (IP) address.
8. The network according to claim 4 , wherein the third wireless switch and any wireless switch configured to be part of the second mobility domain are configured with a second mobility domain string identifier (MDSI).
9. The network according to claim 8 , wherein the third wireless switch is not configured with the common mobility domain string identifier (MDSI) and is not part of a first mobility domain.
10. The network according to claim 1 , wherein the data tunnel comprises a GRE-over-IP data tunnel, between the first wireless switch and the second wireless switch, which operates according to GRE-over-IP.
11. The network according to claim 10 , wherein in the GRE-over-IP data tunnel each L2 packet comprises L2 header information such that a destination end of the GRE-over-IP data tunnel receives the L2 header information.
12. The network according to claim 10 , wherein the L2 header information is available at the destination wireless switch of the GRE-over-IP data tunnel, and wherein the L2 header information of each L2 packet comprises a VLAN identifier.
13. The network according to claim 10 , wherein the control connection comprises a peering session over Internet Protocol (IP).
14. The network according to claim 10 , wherein the peering session over IP operates according to the transmission control protocol (TCP).
15. The network according to claim 14 , wherein the wireless client device mobility related control plane information comprises mobility update messages.
16. A method for creating a mesh network of peer wireless switches, comprising:
discovering, at each wireless switch in a mobility domain, other wireless switches in the mobility domain upon joining the network;
establishing, at each wireless switch in the mobility domain, a peering session with each of the other switches within a mobility area of the mobility domain, wherein a first wireless switch and a second wireless switch communicate with each other over a data tunnel to exchange complete Layer-2 (L2) packets between the wireless switches;
establishing a control connection, at the first wireless switches in the mobility area, a peering session with the second wireless switch in another mobility area of the mobility domain thereby providing a fully meshed network without requiring each wireless switch to have a peering session with every other wireless switch, wherein the control connection comprises a peering session configured to transfer wireless client device mobility-related control plane information between the first wireless switch and the second wireless switch, such that a wireless client device retains an L3 address when roaming between the first and second wireless switches.
17. The method according to claim 16 , wherein establishing, at each wireless switch in the mobility domain, a peering session with each of the other switches within the mobility domain, comprises:
establishing a data tunnel between each pair of the wireless switches in the mobility domain which operates according to GRE-over-IP, wherein each L2 packet comprises L2header information, wherein the L2 header information is available at the destination wireless switch of the data tunnel, and wherein the L2 header information of each L2 packet comprises a VLAN identifier.
18. The method according to claim 17 , wherein each control connection comprises a peering session over Internet Protocol (IP) which operates according to the transmission control protocol (TCP).