I am investigating several design options for our new WAN. I would appreciate your thoughts on these options for this new network:
1) pair of 7206 routers connected to MPLS cloud. The routers connect back to a pair of 6506 switches that support VSS technology using GigE interfaces
2) pair of 6506 switches that interface directly to the MPLS network and to the internal switched Ethernet network
Any merits/drawbacks to either option (besides cost)? Redundancy is a key requirement but so is network management, sustainability, and reduced complexity. Thank you.
7200 have a lot of more feature available than the 6500. For example you will have all the QoS support on the 7200. You will need SIP card on the 6500 to have similar QoS feature.
Also If you loose a 6500 chassis, you still have the two links to your MPLS cloud (assuming your access switches are dual connected)
a possible concern with C7206 is the traffic volume:
C7206 are fine for up to 600 Mbps of traffic.
So if you can expect to be able to handle a bigger traffic volume is better to use the two 6506 directly.
As Laurent has explained the C7206 has got more features.
It could be interesting to compare the cost of a SIP linecard with that of a whole C7206 chassis. (It may be bigger)
Hope to help
On the issue of complexity, if you terminate MPLS directly to the VSS 6500s you only have "one" rather than "three" L3 devices in your topology and to manage. That can work both for you and against you.
As the others have noted, having the WAN routers should provide more features. QoS has been mentioned, but another that might be of interest would be OER/PfR. 6500s are also weaker in this feature compared to the 7200s.
You didn't mention how much WAN bandwidth you need to support, and what the WAN hand-off might be. If the hand-off is Ethernet, you might just use a "LAN" Ethernet ports. For both 6500 "WAN" ports (including Ethernet) or external routers, you'll should carefully select the device to insure it can handle the expected load and hand-off connectivity. (For example, might a 7301 or 7201 be used instead of a 7206? SIP-200 or SIP-400?)
Thanks for the feedback guys. As far as WAN BW, we are looking at multiple 300Mbps interfaces and a 150Mbps interface connecting to our side. No video and some voice. WAN hand-off is Ethernet. LAN interface back to switched ethernet network is GigE with some 10GigE.
What is OER/PfR?
"What is OER/PfR?"
Tons of information on both on Cisco's site. Much better explanations than I could provide. (NB: BTW, they're one and the same, but OER is sort of ver. 1, and PfR is sort of ver. 2.)
Thanks. I did some additional reading on these 2 features. Pretty good stuff.
I just learned a new requirement. The WAN device must support GET VPN. I know the 7200 series routers support this but I do not think the 6500 series switches do.
Thank you all for your help. We've decided on the 7200 series routers for our edge routers. They have some nice features that the 6500 series don't offer out of the box.