HCX Network Extension BW/Throughput Limit on stretched VLAN

[pinnaca_ravi]

Can someone help me with last point in the above screen shot from VMware document. 850Mbps to 1Gbps NE throughput per network flow. Does this mean max 1Gbps for a single stretched VLAN on NE appliance ?

[ChrisFD2]

No, it means a single SMB flow or other protocol related from from a client to a server. NE appliances will do 4-6 Gbps total throughput.

[pinnaca_ravi]

Hi Chris, I am not seeing the NE uplinks showing more then 1Gbps through put on realtime stats. Also i see below statement from IBM document. Please confirm

"Bandwidth of a single network extension is theoretically 4 Gbps. However, this value can be the limit for all stretched networks within a single network extension pair and is not achievable by a single stretched network. A single stretched network can achieve ~1 Gbps if enough underlay bandwidth is allotted and the latency is low (<~10 ms)."

Reference: https://cloud.ibm.com/docs/vmwaresolutions?topic=vmwaresolutions-hcxclient-vcs-mesh-deployment

[ChrisFD2]

Hi, what is the MTU of the uplink and do you have HCX Traffic Engineering enabled? If not, consider MTU size, as it can affect performance. I'm not sure how IBM are testing, we are able to achieve 6 Gbps+ on a single stretch between VMC on AWS SDDCs via a VTGW.

[pinnaca_ravi]

We are using AVS for cloud SDDC. MTU: 1500 by default on AVS and onprem is also 1500MTU, We are using HCX advanced edition. Traffic engineering is part of HCX enterprise edition.

[lvaibhavt]

Is the stretched network going over IPSEC VPN or express route?

[pinnaca_ravi]

Express Route with 5Gbps to Azure Globalreach

[ChrisFD2]

HCX NE adds a 150 byte header, it's recommended to use an MTU of 1650 or higher to avoid fragmentation and improve performance, especially if you aren't using Enterprise features.