Before buying an RPS for Cisco Catalyst Switches

MustafaAksu — Wed, 07 Jan 2009 12:18:22 +0000

There are two issues that you have to be aware of when you are evaluating RPS solutions for fixed Cisco catalyst switches. Cisco has a product named Cisco Redundant Power System 2300 (RPS 2300) for the non-modular switch series like Catalyst 3560, Catalyst 3750. This is the successor of old Cisco Redundant Power System 675 (RPS 675).

You have only one bullet in your gun when you have an RPS

Switch draw power from RPS after power fail

You can provide a limited redundancy to your network by installing an RPS for your Catalyst Switches. Switch survives without rebooting when main power goes off. It draws power from RPS, but it never return back to main power. An orange LED shows the switch powered by RPS. If you press the standby/active button on the RPS, your switch will reboot and become a normal operation. The only exception is E series switches + RPS 2300 combination. This combination could restore power state without rebooting.

RPS supports only one switch(in some cases two) at one time

Some of the switches will fail with a power circuit fail

You can attach up to 6 switches to an RPS, but if power Circuit 1 fails as shown in the above scenario then RPS only can support one switch and the rest will fail. RPS 2300 can support 2 switches if power requirements are moderate, but no more.

Cisco 3845 Router Product Review

MustafaAksu — Fri, 24 Aug 2007 23:15:14 +0000

Overview
The first impression of Cisco 3845 router on me was that I felt it is too heavy.So, do not try to install it to rack alone. It has two internal power supplies (one by default). Don’t forget to order the redundant one, if you plan to run it for critical business.

The LAN connection is also redundant with two build-in Gigabit Ethernet interfaces. The good thing the GE 0/0 interface has SFP option. You can reach the far LAN Edge points on a Campus LAN. Another alternative is to use it for Metro Ethernet.

High capacity memory is another powerful feature of this router when compared with 2700 series routers. This router comes with 256 MB memory and you can upgrade it up to 1 GB. This really costs too much if you use original Cisco memory, but OEM alternatives exists in the market.

There is one integrated Virtual Private Network (VPN) Module. This module is added for the performance of encryption and not mandatory for VPN, but as Cisco says, it increases the speed 10 times. I did not use VPN on this router, but it looks capable of handling higher loads.

There are 4 HWIC slots and 4 NM slots. It has almost every kind of modules (Etherswitch, wireless controller, ATM, T1/E1, NAM !!! ,FXS,FXO etc.)

My Experience
I use one of these routers for the Internet access with Advanced Enterprise IOS. BGP running on it with full table, cef enabled, Reflexive IP access list exist on the router. I also use it as a router firewall (Security guys call it as choke point). The CPU utilization is just about %2 – 3. I have to accept that this router was a bit oversized for my needs. I could have saved $3,500 (from list prices) if I use Cisco 3825 router.

You have to ask below mentioned questions before decide to buy a Cisco 3845 Integrated Services Router.
- Do I need more than 256 MB memory?
- Do I have several voice clients?
- How much concurrent VPN connection is expected?
- Do I need speeds like E3/T3?
- Do I need different kind of functionalities on one router (e.g. Wireless, ATM, Etherswitch ports)?
It is waste to invest money unless your answers for more than two questions are in affirmative.

Cisco Networking Answers » product review

Before buying an RPS for Cisco Catalyst Switches

Cisco 3845 Router Product Review