Designing a network
A user recently asked this question via e-mail:
I want to design a network, the specification is given below. Can you help me in this regard.
Specification are
1) We have 7 site.
2) Each site have about 250 user and site one have 500 users
3) Exchange server, Mail server should be located at main office
4) The VPN connectivity should be established between offices by using cisco routers.
5) The VPN connectivity should be over ADSL Line have 4 MB bandwidth
6) ISA server will be used as firewall / proxy server.
Can you make a design for that?
Software/Hardware used:
Software/Hardware used:
ASKED:
February 19, 2009 2:24 PM
UPDATED:
February 20, 2009 8:26 PM
Answer Wiki:
Sounds like you have a basic design plan already. One critical element is the circuit provider who can service all of your locations. You need a telecom partner(s) that can meet your uptime requirements and offer pricing at the level appropriate to the service(s) you require. Are you managing this yourself? If you don't have any Cisco or VPN expertise, then this could be a large challenge to handle. Some telecom providers like ATT or Sprint can help with management. Alternative management solutions would include virtual network operators like <a href="http://www.virtela.com/">Virtela</a>. Their network uses multiple providers across the backbone so an outage in one provider's network does not take down the customer's networks. However, remember the "last mile" is always the most fragile and susceptible to problems. I have had good experience with Virtela across a multi-site, multi-national network. I don't have to worry about the daily management of the routers, circuits and performance issues.
Good luck and feel free to ask for additional information from your provider. Don't be afraid.
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Dsl lines and 250 users does not sound like a big enough pipe for all the traffic. Look up MPLS with dedicated T1′s, your upload speed with this many users will be at a crawl across a dsl line. Just my opinion though. I would rethink the whole dsl part of this plan, and go with a carrier who will manage the routers if this is at all possible. Again this is just my opinion without knowing why you chose dsl, there could very well be a reason.
I have sites with a T1 servicing >200 users for site to site communications. They have a separate DSL link just for internet traffic.
It all depends on what is running across the link and expected performance for the users.