Help understanding vpn tunnel bandwidth affects on traffic

[loveroots]

Dear expert I am confuse with physical actual size and VPN tunnel bandwidth.For example office has a T1 mpls ckt 1536. At this location we are using DMVPN tunnel with a bandwidth size of 512k. I had a report about slow performance, when I did a sho interface the physical interface reliable tx load was 50/255 and rx load was 125/255 when I checked tunnel interface the tx load was 10/255 and rx load was 255/255 I wonder if this mean that the tunnel is rece 100% of traffic in the amount of 512k and any traffic over will be place in a buffer or dropped until space is available, please explain as this office normally report slow perform any time when tunnel tx or rx load is max out, once tunnel tx or rx load is not max out office works fine. I also checked in concord ehealth and did notice if the graph for the physical interface is 50 % the tunnel will be at 100% do this mean 1005 of the 512k what is on tunnel interface bandwidth

 

[Minue]

Hello
How many sites do you have that are using VPN?Also what's the link speed for HUB and spoke sites.

Regards

 

[loveroots]

Hi Expert hub is 6megs mpls and spoke are T1 mpls circuit. When using concord physical interface does not show much traffic, but when checking tunnel interface on hub which has 512k bandwidth it some times show 100% utilization on receive or transmit load. tx/rx load 255/255. bandwidth on tunnel for spoke are 512k

 

[Minue]

This is normal because the tunnel interface is using more than 512K.The physical interface is obviously set or has default to a much higher bandwith.The tx/rx load is calculated on the interface bandwith,not the real speed of the link.
Also note the bandwith command doesn't influence the ammount of traffic that will pass on a link.It all depends on the physical link speed and maximum guarantee rate contracted with your ISP.
When the tunnel hits "255" and your user start complaining this means that your ISP is giving a lot less that T1.
Regards