Table Of Contents

Network Infrastructure Considerations for a Messaging Network Controlled by Cisco UMG

TFTP and FTP Servers

FTP Server Configuration Guidelines

Endpoint Software Versions Supported

Cisco UMG Sizing and Network Capacity

Locations to Install Cisco UMGs

Date and Time Management in UMG-Controller Messaging Network

Domain Name Server in a Cisco UMG-Controlled Messaging Network

Network Infrastructure Considerations for a Messaging Network Controlled by Cisco UMG

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First Published: February 28, 2008

This chapter discusses how to prepare to deploy Cisco UMG in your messaging network. Topics addressed in this chapter include:

•Choose TFTP and FTP servers for Cisco UMG installation, backup, and restore

•Choose endpoint software versions (Cisco Unity Express, Cisco Unity, and Avaya InterChange)

•Choose Cisco UMG hardware based on message network scalability and sizing

•Choose the locations that Cisco UMGs will be installed

•Choose NTP servers for date and time synchronization between Cisco UMG and its endpoints

TFTP and FTP Servers

Similar to Cisco Unity Express, Cisco UMG boot loader uses TFTP to load the RAM-based Linux kernel from a network location as the first step of software installation or upgrade. FTP is used for the remainder of the software installation, upgrade, and for backup and restore communication.

Setup the FTP server so that all Cisco UMGs using it have reliable, high-speed, and secure access to the FTP server. Consider the following:

•Backup and restore bandwidth required— The size of the backup depends on the number of nodes registered with the Cisco UMG, the storage capacity of each site, and backup/restore options (configuration only or configuration + data with much higher bandwidth requirement)

•Security of the FTP connection — A Cisco UMG backup or restore operation transmits directory information of subscribers over the FTP connection. If ensuring the privacy of this information is important, use IPsec technology between the Cisco UMG site and the FTP server.

•Security of information on the FTP server — A Cisco UMG backup is stored unencrypted in files on the FTP server. Ensure that access to the FTP server's accounts and disk drives are secured from tampering and unintended access. Choose strong passwords for FTP server account access.

•Cisco UMG access to the FTP server — Ensure that Cisco UMG can access the FTP server by either name or IP address. If the FTP server is accessed by name, then ensure that Cisco UMG is DNS enabled. Any firewall between the FTP server and Cisco UMG must allow FTP traffic to go through.

FTP Server Configuration Guidelines

Each type of FTP server is configured differently. This section provides only general guidelines for the types of features and characteristics your FTP server needs to work with Cisco UMGs:

•The FTP server must support PASV mode (PASSIVE FTP). Ensure that PASV mode is enabled on the FTP server (if there is an option for this).

•Do not use anonymous FTP for Cisco UMG Backup and Restore.

•Use the default port (port 21) for the FTP server.

•When creating user accounts, ensure that each user account is assigned a different home directory.

•Give full permissions to the user over the home directory. Ensure that the user account can upload and download files. Also ensure that the user can create, modify, delete, and rename files and directories from the home directory.

•Ensure that there is enough disk space on the FTP server. Regularly monitor the disk space on the FTP server.

•If a specific directory is configured as the backup directory for Cisco UMG, do not manually delete any files or directories from the directory configured on Cisco UMG.

•If a single FTP server is used to store backups from multiple Cisco UMGs or is shared with Cisco Unity Express, ensure that the directory for each Cisco UMG and for Cisco Unity Express is different.

Endpoint Software Versions Supported

The Cisco UMG supports the following endpoints with versions of:

•Cisco Unity Express 2.0 and higher versions

•Cisco Unity 4.05 and higher versions with Exchange only

•Avaya Interchange version 5.4 only

Cisco UMG 1.0 supports endpoint autoregistration with Cisco Unity Express 3.1 and higher versions only. Customers can stay with the older version of the Cisco Unity Express with manual provision all Cisco Unit Express information on the Cisco UMG. The benefit of this approach is that any existing Cisco Unity Express features will not be broken by an upgrade to a newer version. The trade off will be the flexibility and easy management introduced by auto registration with Cisco Unity Express 3.1 and higher versions. Because the automatic directory exchange is not supported between older versions of Cisco Unity Express and Cisco UMGs, all subscriber information on the Cisco Unity Express must be manually configured on the Cisco UMGs. When you make modifications on Cisco Unity Express, you must also manually update Cisco UMG. Certain features like spoken-name confirmation across multi-mail systems are be supported.

We recommend that you use Cisco Unity Express 3.1 and higher versions. This requires a full regression test of the existing Cisco Unity Express features on Cisco Unity Express 3.1 before deploying the Cisco UMG into the network.

When integrating Cisco Unity with Cisco UMG, Cisco Unity needs to work with Microsoft Exchange only (MX records are required for Cisco UMG). Avaya Interchange versions other than 5.4 are not supported by the Cisco UMG 1.0.

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Note Cisco Unity with Domino is not supported with Cisco UMG 1.0

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Cisco UMG Sizing and Network Capacity

Cisco UMG hardware has two forms, NME-UMG with a maximum of 250 nodes support, and NME-UMG-EC with up to 1000 nodes support. The number of total subscribers who can be supported are 12,500 on NME-UMG and 50,000 on NME-UMG-EC. The number of subscribers is calculated based on 50 subscribers on any single Cisco Unity Express node which is registered with Cisco UMG. The Cisco UMG capacity is tied to both the maximum number of nodes support and the maximum number of subscriber support that comes first. For example, if the Cisco UMG network has Cisco Unity and/or Avaya Interchange endpoints with a large number of subscribers, the number of nodes which can register on the UMG will be significantly less than 250 or 1000.

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Note We recommend NOT mixing the NME-UMG-EC and NME-UMG hardware on the Cisco UMG primary and secondary pair setup.

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The topology between the Cisco UMG and its nodes (Cisco Unity Express, Cisco Unity, or Avaya Interchange) is a hub-n-spoke. However Cisco UMG connects other Cisco UMGs in the same network with fully meshed topology. A complete Cisco UMG controlled messaging network can connect up to 20 Cisco UMGs (10 primary Cisco UMGs and 10 secondary Cisco UMGs as a fully redundant deployment) with total of up to 500,000 subscribers.

Below is the licensing information about Cisco UMG:

•Basic license levels thatyou can order with product

– UMG-LIC-25

– UMG-LIC-100

– UMG-LIC-500

– UMG-LIC-1000

•Additional license levels that you can added when ordering Cisco UMG

– UMG-LIC-25-UPG

– UMG-LIC-100-UPG

•Additional spare licenses you can add later

– UMG-LIC-25-UPG=

– UMG-LIC-100-UPG=

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Note Aditional licenses can be ordered as spare licenses; however, upgrading a license from 250 nodes to a higher number may require purchasing the higher capacity hardware (NME-UMG-EC) if the original module is NME-UMG.

When purchasing Cisco UMG, preorder a Cisco Integrated Services Router ( Cisco ISR) with a network module slot.

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Locations to Install Cisco UMGs

As an application running on the Cisco ISR network module, the Cisco UMG can be installed on any Cisco ISR with a network module (NM) slot. Although the Cisco UMG software cannot be coresident with the Cisco Unity Express on the same NM, the Cisco UMG software can be installed on a separate NM slot but co-resident with Cisco Unity Express NM on the same Cisco ISR. The Cisco ISR can run Cisco Unified Communication Manager Express, Cisco Unity Express, Cisco UMG, gatekeeper, or any other IOS features from Release 12.4(15)T or higher.

When considering the location to install the Cisco UMG, the following factors should be taken into account:

•Is a spare Cisco ISR NM slot available in the current network? For example, if there is gatekeeper Cisco ISR with an extra NM slot open, installing Cisco UMG on the same router will consolidate both Voice and messaging network endpoint management, and eliminate a request for an extra Cisco ISR.

•Traffic pattern and characteristics on the current network. Besides the extra network traffic during endpoint registration, directory exchange, and Cisco Unity Express remote lookup, the Cisco UMG acts as proxy for message delivery between two registered endpoints. It is recommended to install the Cisco UMGs at the edge of each region, such that no extra WAN traffic will be introduced back and forward across regions during the message delivery.

•When deploying Cisco UMGs with redundancy, the primary Cisco UMG does not need to be the same location as the secondary Cisco UMG; however we recommend you install the secondary Cisco UMG in the same graphic region or area as the primary Cisco UMG. A reliable IP connectivity between primary and secondary Cisco UMGs is also required to reduce the directory information out-of-sync possibility. Comparing to a communication system with redundant call control agents, the Cisco UMG redundancy does not have strict delay restriction because of the nature of VPIM traffic, although less network delay is preferred.

Date and Time Management in UMG-Controller Messaging Network

Similar to Cisco Unity Express, Cisco UMG configures date and time via two system configurations:

•Time zone and geographic area configuration

•Network Time Protocol (NTP) source

With a NTP server which is Coordinated Universal Time (UTC) and the time zone setting (the offset from UTC to local time) in the network, the clock is synchronized with the NTP source during Cisco UMG software startup.

We recommend the following practices for optimal date and time control:

•Use a robust NTP server in the network for maximum clock stability.

•Synchronize all the mail systems with the NTP source in a Cisco UMG controlled messaging network. An NDR may be returned to the messaging sender if time out-of-sync exists between endpoints and Cisco UMGs.

•Use the Cisco UMG hosting router (or any other low-end router) as the NTP server only as a last effort. A host router can easily incur clock drift and does not contain batteries to maintain clock settings over a power cycle.

•Use multiple NTP servers to enhance the reliability of clock synchronization and server availability.

Domain Name Server in a Cisco UMG-Controlled Messaging Network

Cisco UMG and the Cisco Unity Express endpoints can choose to use IP address to address each other, instead of DNS hostname. The benefit of this approach is to improve the message exchange performance without involving the DNS lookup.

When DNS is enabled in the network, Cisco UMG performs a reverse DNS lookup to resolve the inbound IP addresses to the hostname. If one or more Cisco Unity nodes exist in the network, Cisco UMG must be assigned with a MX-record and hostname in the Cisco Unity DNS domain. When you configure the Cisco Unity node on the Cisco UMG, the hostname field can be a Cisco Unity IP address, Cisco Unity A record, or Cisco Unity MX record depending on how Cisco Unity DNS resolves the addresses.

When deploying the Cisco UMG redundancy with a Cisco Unity system, two MX rewords must be assigned to the Cisco UMG with the same Cisco UMG hostname but different IP addresses and different priorities. From the perspective of Cisco Unity, the primary and secondary Cisco UMGs are transparent because this information is configured only on the DNS server. The primary and secondary Cisco UMGs share the same hostname but with different IP addressed and different priorities on MX records. The Cisco Unity node sends an outgoing message to a Cisco UMG with higher priority (primary Cisco UMG), If the primary Cisco UMG fails, DNS returns the secondary Cisco UMG IP address to the Cisco Unity node with a lower priority to route and deliver the messages.

See the Cisco Unity System Administrator Guide for detailed information about configuring the Domain Name Server.