Home Lab (Router Selection)

This blog entry will cover some of the router hardware you can purchase in your home lab for gateway and Cisco Unified Communications Manager Express (CUCME). If you plan on running CUCME, you will need to buy at least a 2610 XM router. The XM in the router model stands for extendable memory. The 2600 XM series routers allow larger capacities of Flash and DRAM than the non-XM variants. The 2600 XM series routers are selling on E-Bay very, very cheap. Unfortunately, the 2600 XM routers do not supported the CUCME 4.3/7.0. The 2600 XM router does support CUCME 4.0. If you’re on a tight budget, I highly recommend the 2600. If money is not as tight, I recommend you purchase one of Cisco’s Integrated Services Routers (ISR). The 2801 ISR router is the cheapest in the ISR family, but it should give you most of the flexibility you need for a smaller home based lab. As of this writing, there are multiple E-Bay listings for used 2801 routers at slightly over $1,000-. While there are many router options to choose from, any router that is not in the ISR family will have limitations. I recommend that you start your lab off with an older 2600 series router and upgrade to a 2800 series router when you have the budget. I do not recommend the 800, 1600, 1700, or 1800 routers because they have too many limitations. If you want to test T-1 gateway functionality, you are going to need two routers with T-1 interfaces. Since this can be quite expensive, you may want to forego testing T-1 interfaces unless you have a larger budget. For those that will be testing T-1 interfaces, I highly recommend buying at least a 2811 router. The 2801 router has (2) HVWIC (High-Density Voice WAN Interface Cards), while the 2811 supports (4) HVWIC slots. I’m assuming that everyone will want to test FXS (Foreign eXchange Station) and FXO (Foreign eXchange Office) interfaces. These interfaces will consume two HVWIC slots. The 2811 router will cost you an extra $200-, but it well worth the extra money. The 2811 will give you some investment protection and the highest level of flexibility. This router is definitely my recommendation if you can afford it. Start out with a 2601 XM if you cannot afford this router right now. If you would like to peruse the different hardware capabilities of all the ISR routers, I have created an easy link to the long Cisco URL: http://tinyurl.com/2800isr Once you have a router, we will need some voice interfaces to test the gateway functionality of the router. Recall that a gateway converts VoIP RTP bearer streams into a time division multiplexing (TDM) format bi-directionally. The conversion functionality requires digital signal processors (DSPs). The DSPs can be quite expensive, so you will want to be very conscientious of price during this selection. Cisco has a DSP calculator on their website to help out with this, but the calculator requires you to logon with your CCO username/password. The URL for the DSP calculator is http://www.cisco.com/go/dspcalculator. The ISR (2800/3800) routers have PVDM2 (Packet Voice DSP Modules) slots on the motherboard. The PVDM2 slots look like memory (Flash/DRAM) slots. The cheapest PVDM2 module is a PVDM2-8 which will fetch nearly $125.00 (US) on the used marketplace. The PVDM2-8 does not support hardware conference bridges though and will greatly limit the hardware media resource configurations (transcoders, MTP, and conference bridges) that will be able to register with Cisco Unified Communications Manager (CUCM). The PVDM2 module will cost nearly $200-, but I highly recommend that you buy at least a PVDM2-16. The older routers do not have any onboard DSPs. DSPs will be on the network modules. I will cover this in future blog posts. The next blog post will continue the gateway hardware configuration discussion. We should start discussing HWIC cards to provide voice gateway interfaces.