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Roaming across AP6521 and AP7522


Due to the end of sale of AP6521 I am now encountering the situation where customers require additional access points. The scenario is AP6521 with Virtual Controller installed in a warehouse and now needs some additional access points. If I propose AP7522 with Virtual Controller will there be roaming problems when devices roam across the two models? devices will be running Wavelink TelnetCE. Any thoughts appreciated, Regards Steve

10 replies

Userlevel 3
Hi Steve, as I understand it you will effectively be running two separate Wi-Fi networks and therefore when clients need to roam they will disconnect from one LAN and need to re-associate with the other LAN.

Wi-Fi roam-assist mechanisms such as 802.11k, r and v are usually implemented in the controller software and as the virtual controllers won't be aware of the other APs, these mechanisms won't operate.

Have you considered implementing a Wireless LAN Controller (e.g. RFS4000) that can adopt both the older and new APs to remedy this situation?

Hope that helps.

Best regards,
Darrel.
Darrel Rhodes wrote:

Hi Steve, as I understand it you will effectively be running two separate Wi-Fi networks and therefore when clients need to roam they will disconnect from one LAN and need to re-associate with the other LAN.

Wi-Fi roam-assist mechanisms such as 802.11k, r and v are usually implemented in the controller software and as the virtual controllers won't be aware of the other APs, these mechanisms won't operate.

Have you considered implementing a Wireless LAN Controller (e.g. RFS4000) that can adopt both the older and new APs to remedy this situation?

Hope that helps.

Best regards,
Darrel.

Thank you Darrel, It looks like an RFS4000 is the sensible answer.
Userlevel 3
Darrel Rhodes wrote:

Hi Steve, as I understand it you will effectively be running two separate Wi-Fi networks and therefore when clients need to roam they will disconnect from one LAN and need to re-associate with the other LAN.

Wi-Fi roam-assist mechanisms such as 802.11k, r and v are usually implemented in the controller software and as the virtual controllers won't be aware of the other APs, these mechanisms won't operate.

Have you considered implementing a Wireless LAN Controller (e.g. RFS4000) that can adopt both the older and new APs to remedy this situation?

Hope that helps.

Best regards,
Darrel.

My pleasure Steve! Please let me know if you need any further assistance or help with the procurement of a controller. If you run virtualisation software, the VX is great value.
hi,

my experience showed me that the best for your situation will be installing a controller (vx, rfs4k or nx) to use all features and roaming assist implementations of wing.

otherwise your clients will behave like darrel wrote.

nr
richard
Richard Muehlberger wrote:

hi,

my experience showed me that the best for your situation will be installing a controller (vx, rfs4k or nx) to use all features and roaming assist implementations of wing.

otherwise your clients will behave like darrel wrote.

nr
richard

Thanks Richard. I agree its the sensible approach
Userlevel 2
Hi Steve
How Many Access Points 6521 Do You Use?

And how many Aps7522 will you add?

The Wavelink Telnet emulator is very sensitive to roaming and can suffer a disconnection so I understand your concern.

What HanHeld uses Zebra MC9000 or Intermec??

I recommend using a Telnet session manager that will help you not to suffer disconnections in Telnet clients.

http://www.wavelink.com/Download-ConnectPro_Session-Persistence-Software/
Edmundo wrote:

Hi Steve
How Many Access Points 6521 Do You Use?

And how many Aps7522 will you add?

The Wavelink Telnet emulator is very sensitive to roaming and can suffer a disconnection so I understand your concern.

What HanHeld uses Zebra MC9000 or Intermec??

I recommend using a Telnet session manager that will help you not to suffer disconnections in Telnet clients.

http://www.wavelink.com/Download-ConnectPro_Session-Persistence-Software/

Thanks Edmundo, I hadn't thought about ConnctPro to provide session persistence. They will be MC9000. Around 8 new APs going in. I think adding a controller is the best option to bring all access points under a single management. If it was only 1 or 2 APs that might be a hurdle cost-wise
Userlevel 2
Edmundo wrote:

Hi Steve
How Many Access Points 6521 Do You Use?

And how many Aps7522 will you add?

The Wavelink Telnet emulator is very sensitive to roaming and can suffer a disconnection so I understand your concern.

What HanHeld uses Zebra MC9000 or Intermec??

I recommend using a Telnet session manager that will help you not to suffer disconnections in Telnet clients.

http://www.wavelink.com/Download-ConnectPro_Session-Persistence-Software/

Yes
By the amount of Acces Point the best option would be an RFS4000
Hello Steve,

If you are installing the new APs (AP7522) behind a routed switch, then for seamless roaming to be achieved, a controller (RFS4000, NX5500, VX9xxx) is needed as mentioned above; however, if these new APs are going to be in the same broadcast domain as the AP6521s, then seamless roaming (required for telnet) is possible without the need of a fully fledged controller. It is important to note that 2 virtual controllers in the same broadcast domain is not recommended and not supported. Here are some recommendations:

1 - All APs should be on the same firmware version
2 - All APs should be in the same broadcast domain
3 - Leave the AP6521 configure as VC, but add the AP7522 as Standalone APs not adopted by a VC (for now).
4 - Disable MCLP VLAN on the AP7522s

In the upcoming firmware release, heterogeneous VC support should be included. The AP7522 should be able to adopt different models not in the same family. It's not clear if the AP6521 will be included in the list, but we'll know more once the firmware is released.

In short, seamless roaming can be achieved in the following cases:
APs not in same broadcast domain >> full controller
APs in the same broadcast domain >> VC for AP6521 and no VC for AP7522

Regards,

Chris
Christoph S. wrote:

Hello Steve,

If you are installing the new APs (AP7522) behind a routed switch, then for seamless roaming to be achieved, a controller (RFS4000, NX5500, VX9xxx) is needed as mentioned above; however, if these new APs are going to be in the same broadcast domain as the AP6521s, then seamless roaming (required for telnet) is possible without the need of a fully fledged controller. It is important to note that 2 virtual controllers in the same broadcast domain is not recommended and not supported. Here are some recommendations:

1 - All APs should be on the same firmware version
2 - All APs should be in the same broadcast domain
3 - Leave the AP6521 configure as VC, but add the AP7522 as Standalone APs not adopted by a VC (for now).
4 - Disable MCLP VLAN on the AP7522s

In the upcoming firmware release, heterogeneous VC support should be included. The AP7522 should be able to adopt different models not in the same family. It's not clear if the AP6521 will be included in the list, but we'll know more once the firmware is released.

In short, seamless roaming can be achieved in the following cases:
APs not in same broadcast domain >> full controller
APs in the same broadcast domain >> VC for AP6521 and no VC for AP7522

Regards,

Chris

Many thanks for that advice Chris. ALL APs will be in the same broadcast domain. I'm not too sure but hopefully the host will also be in the same domain -

I had a site with APs in autonomous mode many years ago and ran a trace on a hand held to capture network packets and on roaming if my memory is correct the hand held would request DHCP then request 'who has default gateway' and then when it tried to reach the host (in a different country) it had a few timeouts. This caused the Telnet 5250 client to X-Wait. All APs in that scenario were on the same IP network but the host was reached via the site gateway. Once the APs were adopted to a centralised controller the problem was resolved.

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