Re: bandwidth of a vpn tunnel

You need to know your packet size distribution and what kind of IPsec transform (tunnel/transport ESP/AH ...) is used.

The later gives you the overhead per packet.

If your average packet size is large, the IPsec overhead will not cause a bandwidth issue provided that your clear text bandwidth is OK.

If your average packet size is small (like < 200), the IPsec overhead can be a major issue is your bandwidth utilization is  already high.

NB: the above assumed that your VPN equipment have enough CPU/HW acceleration to handle the require bandwidth

Hope this helps

-eric

At 09:47 12/11/2004 -0600, jeremy oliver wrote:
>Well I have several IPSEC VPN tunnels created between remote locations
>back to my corporate office.  I am adding more such tunnels everyday
>and was wanting to figure out a way to see how much bandwidth a tunnel
>eats up.  There are anywhere from 2-80 users at the remote facilities
>who are using the tunnel for email and other production applications. 
>Hopefully that is clear enough.
>
>
>On Fri, 12 Nov 2004 09:16:35 -0600, Bill Yazji <[email protected]> wrote:
>> Your question is quite vague.  Is your VPN tunnel being used for a control
>> ping to a remote server, or streaming porn movies to 10000 users?
>> 
>> What kind of VPN tunnel is it - IPSec, PPTP ???
>> 
>> You don't have nearly enough information in this to get a even remotely
>> close answer..
>> 
>> ~Bill
>> 
>> 
>> 
>> -----Original Message-----
>> From: [email protected]
>> [mailto:[email protected]] On Behalf Of jeremy
>> oliver
>> Sent: Thursday, November 11, 2004 8:19 AM
>> To: [email protected]
>> Subject: [VPN] bandwidth of a vpn tunnel
>> 
>> Does anyone have any info on what type of bandwidth that a vpn tunnel takes
>> up?  I am creating new lan to lan vpn tunnels all the time and I am
>> beginning to worry about the T1 that I have running into the main office.
>> This T also serves many web sites as well as Internet access for the rest of
>> the company.  I just want to see when I should start to worry and need some
>> fire power to take to the boss.
>> 
>> Jeremy Oliver
>> _______________________________________________
>> VPN mailing list
>> [email protected]
>> http://lists.shmoo.com/mailman/listinfo/vpn
>> 
>>
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