Difference between SLB and ADC

[Addepalli Srini]

Hi,



I see two terms being used - SLB (Server Load Balancing) and ADC
(Application Delivery Control). As I understand both SLB and ADC
devices have ability to perform persistency at HTTP protocol level by
mangling Cookie or generating new Cookie. Is Load Balancer device
called ADC if it has ability to use L7 protocol level fields in
determining the real server? Is that the main difference?



Thanks

Srini

[Tony Bourke]

Hi Addepalli,

They're one in the same. ADC tends to be used more often by the vendors
now, with the argument that load balancers do a whole lot more than the
load balancing they started out doing in the mid 90's. With
caching/compression, IPS/App firewall, SSL, content manipulation, etc.,
vendors tend to prefer the term ADC.

I tend to use the term load balancer, because that seems to be what more
people are familiar with, and it's the term that gets most widely used
in the field. I often joke that if you call such a device a load
balancer in front of a vendor's marketing person, they'll stab you with
a fork. They much prefer the term ADC.

Virtually all load balancers understand Layer 7 these days. I don't know
of a single vendor that only supports L4, although it's possible there
are one or two out there. So again, SLB and ADC are pretty much one in
the same.

Tony

Hi,
I see two terms being used – SLB (Server Load Balancing) and ADC
(Application Delivery Control). As I understand both SLB and ADC
devices have ability to perform persistency at HTTP protocol level by
mangling Cookie or generating new Cookie. Is Load Balancer device
called ADC if it has ability to use L7 protocol level fields in
determining the real server? Is that the main difference?
Thanks
Srini
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[Ravi Kumar]

Gone are the days LB devices are just doing the server load balancing.
Now it became basic feature in most of the networking devices. There are
some firewalls which does load balancing for the DMZ servers.
LB evolved into application delivery controllers( ADC).

Now most of the products have Inline Intrusion Prevention system
integrated protecting the webservers from threats and exploits. SSL
offloading, built in web compression for better network bandwidth
utilization, application intelligence added to their load balancing and
filtering decisions. With many features rich, it suits to give a new
name for the LB.

-Ravi Chunduru.

Hi,
I see two terms being used -- SLB (Server Load Balancing) and ADC
(Application Delivery Control). As I understand both SLB and ADC
devices have ability to perform persistency at HTTP protocol level by
mangling Cookie or generating new Cookie. Is Load Balancer device
called ADC if it has ability to use L7 protocol level fields in
determining the real server? Is that the main difference?
Thanks
Srini
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[Joo Yong-Seok]

Some of them have it.

In alteon case,

- passive Cookie based persistence
- cookie insert
- cookie rewrite

are supported. More details could be found in application guide for alteon.

Best regards,

- yongseok

Hi,
I see two terms being used – SLB (Server Load Balancing) and ADC
(Application Delivery Control). As I understand both SLB and ADC devices
have ability to perform persistency at HTTP protocol level by mangling
Cookie or generating new Cookie. Is Load Balancer device called ADC if it
has ability to use L7 protocol level fields in determining the real server?
Is that the main difference?
Thanks
Srini
_______________________________________________
lb-l mailing list
http://vegan.net/mailman/listinfo/lb-l
Searchable Archive: http://vegan.net/lb/archive
http://lbdigest.com Load Balancing Digest
http://lbwiki.com Load Balancing Wiki