Complete As-Built Documentation
for VoIP Networks

Accurate As-Built Documentation of a Carrier IP network is critical to ongoing successful operation. Put ECG's long experience to work in auditing, updating, and documenting your Carrier IP Network.


  • Details at every layer of the network hierarchy
  • Complete and comprehensive – based on physical and operational audit
  • Provided in spreadsheet (XLS) and clear, PDF format or printed poster-sized diagrams
  • Covers complex issues like MPLS VRFs, IP Subnets, Firewalls, and VLANs


  • Excellent for Due-Diligence research during Mergers and Acquisitions
  • Get a complete view of sophisticated, modern networks
  • Train new staff
  • Provide accurate and complete documentation for vendors and integrators

Application Packet Flow Diagram

These diagrams show the devices and which ones send application-layer protocols to one another. You may have one diagram for SIP, MGCP, and RTP; another diagram for DNS, and NTP; another SMTP and POP3 used for voicemail. This diagram does not show routers or switches. Why include this: this describes which devices really communicate without including unrelated details about network transport or physical connectivity.

IP Subnet Diagram

This is a diagram showing the IP devices and subnets. Router/Firewalls are shown differently than non-routers. I sent an example of this in my email to the centennialpr-voip mailing list. Each oval represents a subnet, and each box represents a Layer-3 device, and each line represents an IP address assignment. (ECG's format is an expansion of Cisco's network diagrams, customized for Carrier networks.) Why include this: this functions as the single master source for understanding packet flows for "pings" and normal packet transmission.

VLAN Table

Each row in the VLAN table includes (a) VLAN ID, and (b) description of the traffic on that VLAN, and (c) all of the IP subnets present on that VLAN, (d) the Ethernet switches involved in this VLAN. Why include this: The VLANs are critical to operation and configuration and limiting traffic flow. It is important to know which Ethernet switches ("bridges") are on each VLAN to make Spanning Tree work properly. Service Providers should also know what VLANs are for so they can be pruned or allowed properly on devices that support 802.1q trunk ports, like the Acme Packet SD.

IP Address Table

Include every address in each subnet listed in the VLAN table. For each IP address, list whether it is (a) ASSIGNED, RESERVED, or VACANT, (b) What device and interface it is assigned to. Why include this: Knowing what IP addresses are in use is critical to troubleshooting traffic based on traces. It's also important to know what IPs are reserved or vacant when assigning new IP addresses.

Device List

List out every physical device. The list should include (a) the name of the device, (b) The OS and software running on that device, (c) what services the device providers, (d) and the physical location of each device – building/room/row/rack/position. Why include this: This functions as an inventory of actual physical devices to understand which ones are being used and how they're being used.

Firewall Rule List

List each rule that governs traffic between the subnets shown in the IP Subnet Diagram. Each rule must be explained. We normally model this after the Cisco Pix/ASA format using Object Groups, Access group, and then statements showing which interface it's applied to. The purpose is to explain how the firewall should be built. Why include this: the IP Subnet diagram shows when traffic should cross a firewall, but this shows us which traffic will cross a firewall.

Static NAT Rule List

For networks that have NAT rules on firewalls or routers, a table or diagram should show where the NAT rules apply. This comes directly from the router or firewall configurations. For each static NAT rule, (a) the device performing NAT, (b) the "inside" interface, (c) the "inside" IP address, (d) the "external" interface, (e) the "external" IP address. Why include this: with NAT in place you need to know where IP addresses changes to properly connect traffic from one network to another.

Cable List

List out each cable and connection; you have one row for each physical cable. We list (a) the Cable ID number, (b) the A-device, (c) the A-port, (d) the A port configuration details, (e) the Z-device, (f) the Z-port, (g) the Z port configuration details, (h) the cable and connector types. Why include this: you need to know where things are connected for analyzing and troubleshooting fault tolerance, and to configure port mirroring. You also need to know how many ports are in use or available on each device for planning growth, and designing new connections.