Need help in network redesign

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Sep 14th, 2008
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I am trying to redesign my network with Cisco devices and would like to have some advise on this. Below are the details and attached the current setup

current setup

Non cisco devices

2 T1s each from a different ISP - /28 networks - one data T1 and one voice and data converged T1

ISPs provide their routers for T1 terminations

Data LAN -

Voice LAN -

Multiple VLANs based on client - each client traffic is NAT translated for outgoing and incoming traffic so each client traffic use different IP from ISP

(some clients are on ISP1 and some are on ISP2)

intervlan routing between all VLANs

Avaya IP office - VoIP system

2 24 port Adtran router/switch/firewall

port forwarding to internal servers from outside

proposed setup

like to move to Cisco devices

2 T1s each from a different ISP - /28 networks - one data T1 and one voice and data converged T1 (I can add more IPs on both ISPs if needed)

ISPs provide their routers for T1 terminations

Single LAN -

Multiple VLANs - intervlan routing

Avaya IP office - VoIP system

Need load balancing on T1s

Need failover over T1s and router failover

2 24 port switches required

port forwarding to internal servers from outside is needed

From the above setup, I would like to know what is the best way to design my network to achieve load balancing on both T1s and having router and network redundancy and what routers and switches I can go with. I am thinking to use 2811 router in which switch port module can be added.

Please advise

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drolemc Mon, 09/22/2008 - 13:52
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Based on the number of users in the branch, three design models can be used, each of which offers a certain amount of scalability. The choice of models is affected by requirements such as high availability, because some of the interfaces on the edge router do not support EtherChannels. If a server farm must be supported in the branch, the design must support the required port density to connect the small server farms and to meet the additional DMZ requirements. High availability, scalability, and advanced services add to the cost of the infrastructure. Layer 2 and Layer 3 switches do provide some alternatives to which software images can be used to keep the cost low while still providing high availability and scalability. Also, the infrastructure can be reused to migrate to advanced services if required without having to redesign.

Voice and data VLANs are configured on the access ports to which the end users are connected. The voice and data VLANs are supported on a single interface and work with Cisco IP phones. Cisco IP phones have a switch inside that supports a 10/100 Ethernet port, which can be used as a data port. Cisco IP phones tag all packets originating from the IP phone with a voice VLAN ID. The data traffic coming from the associated Ethernet interface on the Cisco IP phone is untagged and is associated with the access VLAN on the switch port.


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