Load balancing of traffic depending on the bandwidth of the channel

[dijix1990]

Can we make sdwan does load balancing of traffic depending on the bandwidth of the channel?

if we have two isp's I would like sending traffic depends on channel bandwidth

1 ISP 100 mbit channel

2 ISP 200 mbit channel

[M02@rt37]

Hello @dijix1990,

Yes, SD-WAN technology allows for intelligent and dynamic traffic management across multiple WAN links.

By leveraging SD-WAN controllers or orchestrators, you can configure policies and rules to monitor the bandwidth of each link and make dynamic routing decisions. The SD-WAN controller can continuously assess the available bandwidth of each ISP link and distribute the traffic accordingly, ensuring optimal utilization of the available resources.

[dijix1990]

It's good. Can you share guide or example?

[mdewald]

Maybe this what you're looking for?

https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/qos/ios-xe-17/qos-book-xe/forwarding-qos.html

Regards,
M

[dijix1990]

I think this feature can help, but not shure

https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/qos/ios-xe-17/qos-book-xe/m-adaptive-qos.html

Just need to balance traffic between two wan operators with different bandwith to prevent dropes because of exceeding channel

[Kanan Huseynli]

Hi,

for overlay traffic you can use weight attribute for TLOC. Weight can be between 1-255 and affects both inbound and outbound traffic:

https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/System-Interface/systems-interfaces-book-xe-sdwan/configure-interfaces.html

for DIA, I believe that it is purely ECMP based (depending on ip cef load-sharing algorithm) and weight will not help.

Unfortunately, this type of internals are not documented in detail. If you have TAC support, open case as question.

[MHM Cisco World]

@dijix1990 you get answer from godfather of sd-wan in community @Kanan Huseynli 

So I agree I read now sd-wan and it support ecmp only.

Thanks 

MHM

[dijix1990]

Unfortunately, not for dia and a simple balance between channels, I mean a flexible balance between different channels with different widths

[dijix1990]

So, how can I understand that there is no special function for intelligent balancing, such as fortinet or vmware has, because the weight of @Kanan Huseynli's recommendation does not correspond to intelligent balancing, for example 1/3 or 2/1, or depending on the actual bandwidth of the channel, that is, sdwan does not determine that a 100 mbit wide channel can be sent more traffic than in a 50 mbit wide channel

[Kanan Huseynli]

I don't quite sure, at which level weight is intelligent, but you can use weight 1 for ISP1 (100Mbps), use weight 2 for ISP2 (200Mbps). Plus, better to use shaper additionally on these egress interfaces.

[dijix1990]

Yes I tried it yesterday. It works when bandwith is stable, but if we start decrease bandwidth through shaper or policer we get drops, because edge sends traffic despite shaper. I want to try this https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/qos/ios-xe-17/qos-book-xe/m-adaptive-qos.html. Thought that sdwan from cisco has simple policy for theese situations as sdwan from vmanage/fortinet, maybe it will be later