Cisco 3825 Query

[Vivek Agarwal]

Hi All,

We are having to terminate a Serial Interface Leased Line onto our Cisco 3825 Router. We have two ways of terminating it:

1. The telecom carrier gives us a G703 interface which we connect straightaway to our 3825 router which requires us to install a E1 T1 Card Network Module card on the router
2. The telecom carrier connects his G 703 interface to a G703 to V.35 Converter and provides us with the V.35 Termination. We then connect this to our router with smart serail cable and using  HWIC 1T V03 Card on the router

We would like to know which of the two options is better. As we are in electronic  high frequency trading , We are looking at the faster connection with higher speed support, lower latency and greater throughput.

Awaiting Kind response

Thanks

Vivek Agarwal

[Leo Laohoo]

As we are in electronic  high frequency trading , We are looking at the faster connection with higher speed support, lower latency and greater throughput.

Then your WAN is not suitable for your business.  Serial interface?  That's LOW SPEED.  Even if you are using HSSI it's still low speed.  

Talk to your ISP and ask them about MPLS link.  Instead of terminating serial interface you could potentially terminate either fibre optic or copper.  Much easier to diagnose and troubleshoot.  

Another thing, don't even try to consider/evaluate xDSL solution.  

[Vivek Agarwal]

Hi Leo,

Thanks for your prompt reply. I somehow missed it and realized only now that you had replied.

I do understand your point and to elaborate on it, we are having multiple circuits and most of them we are dedicated ethernet with either optical/copper termination.

However, this particular circuit cannot be a dedicated ethernet/MPLS. The other end only supports Serial Interface (OFC - STM 1). Hence we are forced to take serial interface.

Thus my query now stands at, what do we prefer of the two options given above:

G703 with E1 T1 / v.35 with HWIC 1T

Do let me know. Thanks in advance for your help

[Leo Laohoo]

Thus my query now stands at, what do we prefer of the two options given above:
G703 with E1 T1 / v.35 with HWIC 1T

That'll depend on your ISP.  IF they can support both, I don't see why G703 won't work.  

[Vivek Agarwal]

Hi Leo, both would. However, concern is which one is better in terms of latency and throughput

[Leo Laohoo]

I can't say other will agree with me on this, but you're going to have to ask your ISP.  You can have a T1 and hope to get 1 Mbps link but if your ISP's backbone node is fully congested during office hours (as an example), then you're stuffed.  

Either way won't make any difference.  The ISPs contention ratio plays a significant part.  This is why financial organization pays a fortune to the ISP and holds them to their word on the SLA.  Financial institution don't just have a single/dual link towards a single provider.  They "hedge their bets" and have two or more links but each link goes to a different provider.  Each provider has a different exchange which runs on different power source and/or power feeders.  

Take a good example for here, Australia.  If you  are a government agency, you have access to one of telco's government-only WAN backbone link.  What the telco won't tell you is that there are several "levels" (not just speed).  The lowest level of this government-based WAN link is that EVERYONE is on it.  You'll see your latency creep up, on a 20 Mbps link as an example, significantly after lunch time (and all up to 7 pm).  If you happen to be flush with cash or you got lucky, you'll be on a "defense-grade" WAN backbone where the SLA guarantees you low latency at any time of the day.

This is what is like in the "real world" and not what you'll see on any books or school.  Big difference.