Available bandwidth for GRE tunnels

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What is the average of available bandwidth when GRE tunnels are established between two access points (e.g. 2 x HiveAP 121), or between an AP and a CVG ?
Thanks in advance for your answer.
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Laurent Calais

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Posted 5 years ago

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Mike Kouri, Official Rep

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That depends on the backhaul bandwidth for the APs and CVG and the lowest bandwidth of the intervening networks, or in other words, the thinnest pipe in the path between the two tunnel endpoints. I don't believe we artificially limit the bandwidth that can be consumed for the GRE tunnels.
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Carsten Buchenau, Champ

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For the record, as I was just dealing extensively with GRE tunnels and Ipsec VPN encapuslations:

GRE tunnel encapsulation is very lightweight and does not limit the bandwidth. If, however, Layer2 or Layer3 Ipsec VPNs are configured, which are encapsulating GRE tunnels, THEN we do have a bandwidth limit - depending on the hardware, caused by the Ipsec encryption:

BR100: 5 - 10 Mbps
AP170: 10 - 15 Mbps
AP330: 30 - 50 Mbps

I am mentioning this because auf Laurent's wording: When "GRE tunnels are established between two access points", then we ALWAYS need to have underlying Ipsec VPN layer.

The other method is to create "static Identity-based Tunnels", configured through the USER PROFILE - and causing an AP to establish one GRE tunnel for EACH client connection. In this case we do not have an underlying Ipsec VPN, which also means that all client data is transmitted in clear text between the AP and the tunnel termination point.
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Mark Berndt

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Old topic I know but have a question. Is the 30-50 Mbps per tunnel or the maximum of all tunnels? We have four AP330s set up as concentrators and 190 AP 230s and 330s building tunnels to those concentrators. What can I expect to see as throughput per tunnel and maximum throughput for all combined tunnels on the concentrators? 
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Mike Kouri, Official Rep

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Mark, each AP330 (your tunnel terminators) will handle roughly 30 to 50Mbps worth of tunnels. Having nearly 200 devices tunneling to them means at best roughly 1Mbps of bandwidth available to each tunnel initiator access point. I suggest you look into our CVG, available as a VM for VMWare ESXi, or as a standalone appliance.