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Cisco 1711 Throughput 5

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STick170

IS-IT--Management
Jul 6, 2010
26
GB
Hi all, I'm in need of some help.
I have a Cisco 1711 which I've used to maintain two VPN tunnels for several years. It is currently connected to my ISP's ADSL modem via the 10/100 ethernet port and into my network switch via the integrated 4 port switch.
I currently use a 512kb DSL connection which is soon to be upgraded to a 10mb line, my ISP will supply a new router to replace the modem which I assumed I could just plug into the Cisco 1711 and continue to use my two VPN tunnels as normal. (My external IP address will remain the same)
The people who set up the VPN's on (and supplied) the Cisco 1711 are telling me the 1711 will not be sufficient to route and encrypt the full 10Mbps of internet traffic and thus it will be necessary to install a new router of a specification that is suitable for this type and size of circuit.
They say I need to purchase a Cisco 2821(?) to replace the 1711. I thought as the ethernet port and integral switch both claim to support 10/100 it would do the job just fine. Do you guys see any reason why the 1711 won't work with the faster internet connection or do you think my VPN people are just trying to make some easy cash out of me?
Thanks in advance for any help :)
 
No they are correct, Just because the port says 10/100, it does not mean that the Router can move packets at that rate. with a 1711, you will be lucky to hit 2mpbs With encrypted Traffic. As normal unrestricted forwarding is only 6mbps. Although a 2821 is a little overkill, an 1841 or 2801 will do just fine. The 1711 is really old, with a newer router you see not only speed benefits but also latency as serialization delay will be cut back somewhat./

CCNP
 
Just out of interest, would you consider an 1811 to be a suitable upgrade?
 
mmmm, an 1811 is ok, but not expandable. They are fixed configuration routers. So if you happen to switch service type from Ethernet,dsl,t1 etc. You will need two different routers, while the previous routers I mentioned are expandable.

CCNP
 
Thanks for your answer :) One final question then I'll leave you in peace I promise: As my new circuit is a leased line with no scope for upgrade (10mb is it's maxium speed) I'm unlikely to switch service for a long while, so expandability isn't a huge problem. Is the throughput on the 1811 as good as the 1841 or 2801? Sorry for all the questions but I don't really trust my VPN people, their support is great but I feel their sales dept will try and move the most expensive products they can.
 
The 2801 has the highest throughput, 45 mbps i think, while the 1841 is around 35 and 30 for the 1811. So it will be plenty for your application but not expandable.

CCNP
 
Superb, thanks for all your help :) (I've worked out the star button now, sorry for the delay!!)
 
What about a 1750 series with a VPN Module? Would that barely crack 2 Mbps of throughput with encryption?
 
With the vpn Module, maybe 3-4mpbs. But latency will still be high, it is a very old router.

CCNP
 
Just as an update, my VPN provider are telling me the 1811 will only handle a 4mb line with all the encryption enabled. I can't believe it loses around 87% throughput just because of security. I smell a rat!! Think I'm going with the 1811 and see just how well it copes with 10mb.
 
Your need new vpn people. That is total crap. An 1811 will easily handle 20-25 mbps encrypted. The cisco vpn spec sheet says 40, but that may be a bit optimistic. So in short, They are lying to you. Go with the 1811.

CCNP
 
What causes the latency? Just the processing of the packets?

I'm gonna be putting in an MPLS circuit pretty soon, though I'm running up against a hard deadline for some new business that site is picking up and won't be able to process if my carrier doesn't get things moving.

My 1750 has a WIC-ENET card in it. It's connected to a 3 Mbps Bonded T1 circuit.

If I grabbed an 1841 or 1811 could I just pretty much copy my existing config onto that new router (except for the ethernet0 vs fastethernet0/1 interface) and let it fly or is there a completely different set of commands to be entered for it? Could I use the same IOS image on the 18xx router that I use on my 1750?

Would I see a pretty significant improvement in performance until that MPLS is brought online?


 
The latency is caused from processing packets, it's existent in all routers, The delay added from the act of putting a packet on the line is called serialization delay. The Time it takes a packet to arrive at a destination is Propagation delay/ (+serialization on both ends = total latency) It is existent on all routers, although more noticeable on older routers to to the deprecated architectures. i would not recommended the 1750 if voice traffic will be flowing through it. But for data, it wont really matter.

The 1841/1811 conf will be similar, but not identical for reasons you listed above. Ios Versions are specific to individual platforms. So a 1700 and 1800 are totally different, and a common IOS cannot be used between the two.

CCNP
 
OK, thanks for the info!

I need to bump the performance of that connection until that MPLS circuit goes in so I think I'll drop $700 on a 1841.

One last question though. I'm currently running this IOS image:

IOS (tm) C1700 Software (C1700-K9O3SY7-M), Version 12.3(16), RELEASE SOFTWARE (fc4)

I can not find that version on Cisco's website now, but I think the feature set is:

IP/ADSL/FW/IDS PLUS IPSEC 3DES

I'm looking at the 1841 images right now but they use a totally different nomenclature to describe the feature set. Would this 1841 image contain the same features:

ADVANCED ENTERPRISE SERVICES
c1841-adventerprisek9-mz.150-1.M2.bin
Release Date: 12/Mar/2010
Size: 42046.70 KB (43055812 bytes)
Minimum Memory: DRAM:256 MB Flash:64 MB

Thanks Again!
 
Everything and more, AdvEnterprises is the top tier code. This will change in the later version of the "universal Image" but for now. That is the most "feature rich" image.

CCNP
 
Actually, if this image has the same features of the 1750's image I can grab an 1841 for under $700:

12.4(25c)
c1841-entservicesk9-mz.12.4-25c
 
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