Hello is a cisco 837 capable of using a 7mbit adsl line? (negotiated 8128 ADSL-1 type line)
I mean.. since that router does just NAT and nothing else, is the cpu capable of transferring 7mbit down and 512k up?
thank you
raw thruput figures for IP forwarding:
NAT takes some extra steps over simple IP forwarding, so may not reach these numbers - but you have a bit of headroom
note the perf is usually measured on Ethernet ports - that gives the minimum overhead, so driving the ADSL line may cause an issue.
good luck
Hello just yesterday night I was doing some tests:
I have on the same site, two different ADSL lines:
1) 7M/512 - fast - negotiated 8128 2) 7M/512 - interleaved - negotiated 7616On line 1 I have a C2651XM with 12.4(25b) and WIC1-ADSL (rev C0) on line 2 I have a c837 with 12.4(25b)
From the same site, with wide bandwidth, I download:
1) from the 2651xm , 690Kbyte/sec - (5,3bit) cpu 40% 2) from the c837 , 799Kbyte/sec (6,3mbit) - cpu 75%The configurations are exactly the same. According to
Today I will try with another c837 on the line (1) and I will post the results.
"Stephen" ha scritto nel messaggio news: snipped-for-privacy@4ax.com...
raw thruput figures for IP forwarding:
NAT takes some extra steps over simple IP forwarding, so may not reach these numbers - but you have a bit of headroom
note the perf is usually measured on Ethernet ports - that gives the minimum overhead, so driving the ADSL line may cause an issue.
good luck
The line speeds you have are before ATM overheads are allowed for.
Depending on where you are, there may be some overhead on the line as different operators set up ADSL differently.
However 7 Mbps with ATM overhead is at absolute best case 7 * 48/53 (and then with some added packet header overhead).
so around 6.3 Mbps, then you have Ethernet frame overhead in that.
so item 2 is approx 6.4 Mbps, and that probably means the negotiated rate is a bit over 7 Mbps.
WIC / WIC slots were limited to 8 Mbps - i suspect this was a bus limit for so ADSL may be input + output including internal overhead, so your 7 Mbps down / 512 up may be too much.
Finally you should swap the routers between the 2 lines during testing
- the ISP may have a bottleneck for the IP thruput on a line which reduces the available performance.
Hello at the moment I disabled the c2651xm and replaced it with a Cisco 837. It dowlnoads at a peak of 810Kbyte/sec on line 1, so definitely faster than the C2651xm
The 837 seems to manage better the adsl, maybe because it is born for ADSL line and have a dedicated bus for it, the 2651xm is multipurpose and has a terrible limit on the wic slot + wic adsl.
at the moment I will keep the c837.
One drawback I have is that now I am not able to graph in cacti 0.87g the number of NAT translations. The OID with 2651xm doesn't work on the c837.
some help?
"Stephen" ha scritto nel messaggio news: snipped-for-privacy@4ax.com...
The line speeds you have are before ATM overheads are allowed for.
Depending on where you are, there may be some overhead on the line as different operators set up ADSL differently.
However 7 Mbps with ATM overhead is at absolute best case 7 * 48/53 (and then with some added packet header overhead).
so around 6.3 Mbps, then you have Ethernet frame overhead in that.
so item 2 is approx 6.4 Mbps, and that probably means the negotiated rate is a bit over 7 Mbps.
WIC / WIC slots were limited to 8 Mbps - i suspect this was a bus limit for so ADSL may be input + output including internal overhead, so your 7 Mbps down / 512 up may be too much.
Finally you should swap the routers between the 2 lines during testing
- the ISP may have a bottleneck for the IP thruput on a line which reduces the available performance.
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