priority queueing

[h.wall]

I have a site that has an isdn backup. My problem is once the primary line goes down the isdn line gets taxed and is unusable by the staff who use session based software(telnet app). The sites consist of 2 subnets a public subnet and a private subnet. What would be the easiest way to give my private users priority. Another way would be to block http on the public segment but allow http on the private segment. Any help or pointing in the right direction would be appreciated. Thanks in advance.

[gpulos]

you can setup priority queuing to handle the different traffic needs.

see the following link for info on Priority queuing setup:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_configuration_guide_chapter09186a00800ca59a.html

[Richard Burts]

Harris

Without getting into esoteric things like traffic shaping I believe that there are two queuing approaches that you should consider: Priority Queue and Custom Queue. Priority Queue has a smaller number of queues and is pre-emptive: when a higher priority packet needs to be transmitted it will be transmitted before any lower priority packets. The implications of this are that high priority traffic gets best service and lower priority traffic may suffer (and in extreme cases low priority traffic may starve for bandwidth). Custom Queue has a larger number of queues and is not pre-emptive. Every queue gets a turn at transmission but you can set thresholds so that some queues transmit more than others.

My suggestion would be for you to look into Custom Queue to give your users better service but to give everyone some opportunity to transmit.

HTH

Rick

[tdrais]

Both the above answers will work. I am just a fan of the newer class based method of doing queing. Prioirty queing and custom queing are older and not as flexable as the class based methods.

Most people new to QoS will find it much easier to configure class based. With class based you can match protocol like telnet traffic with simple statements like MATCH PROTOCOL TELENT. Of course you can do it with access lists if you prefer.

There are many option to give traffic better preference but in this case you most likely want to use the BANDWIDTH option and set it to almost the complete link.