RFC791 introduced the Type of Service (ToS) field using the most significant fields of the octet (as explained in the last blog). RFC795 defined the service mappings of the delay, throughput, and reliability bits.
RFC1349 “Type of Service in the Internet Protocol Suite” re-defined the ToS byte as the following:
Precedence – first three bits Read more
TOS – following four bits
MBZ (must be zero) – last bit
Welcome back from the holidays! I hope everyone had a very joyous holiday season and got some rest. Over the past two weeks, I have celebrated Christmas, New Years, and my two son’s birthdays as follows:
John J. Hartmann (Johnny) – 4 years old (December 20th) Read more
Dennis E. Hartmann (Buddy) – 7 years old (January 3rd)
In traditional time division multiplexing (TDM) networks, voice and video calls were dedicated resources from source to destination. Packet based networks use much more efficient statistical multiplexing mechanism that lacks the ability to provide an explicit guarantee to real-time communications (voice and video). Quality of service (QoS) is a network technology that allows administrators to pre-allocate resources to application classes when needed. Read more
A CUCM cluster consists of one publisher server with a read/write (R/W) copy of the database. CUCM 5.0 and later uses an IBM Informix database server. The publisher database is then replicated to the subscriber servers as read/only (R/O). CUCM 6.0 added user facing features (UFF) which allows the subscriber R/O database to have limited write functionality for the following critical features to function while the publisher server is down:
• Extension mobility Read more
• Call forwarding
• Message waiting indicators
• Device Mobility
The distributed multi-cluster call processing model has two or more CUCM clusters. This model is typically used with large organizations that have multiple large sites. A CUCM cluster or CUCME router is provisioned at each site in which local call processing is a requirement. This model is also used for environments where IP WAN links are unreliable or sites are geographically dispersed. The distributed multi-cluster call processing model has the following features: Read more
The CUCM locations Call Admission Control (CAC) mechanism is not turned on by default. CAC should be aligned with the priority queue (PQ) configuration in the WAN. The will PQ QoS configuration with the CAC mechanism will guarantee call quality over the IP WAN. Intermittent call quality issues can result if CAC and QoS are not properly configured. Call Manager uses bandwidth variables of 24kbps and 80kbps for G.729 and G.711 respectively. Read more
Inter-site IP phone calls in the centralized call processing model are routed over the wide area network (WAN). To preserve valuable WAN bandwidth, most organizations compress phone calls with the G.729 or iLBC audio codecs. G.729 compresses audio calls to 8kbps + 16kbps (IP/UDP/RTP encaptulstion) for a total of 24kbps per call. The iLBC audio codec uses 15.2kbps + 16kpbs = 31.2kbps for the same phone call. Although iLBC uses almost twice the codec bandwidth of G.729, iLBC has a higher MoS and a better degraded mean opinion score (DMoS) than G.729. Read more
The centralized call processing model offers toll bypass efficiencies for inter-site calls. Inter-site calls are routed over the IP WAN, instead of using PSTN resources. Inter-site call routing over the data network is commonly referred to as toll bypass because the toll charges of the PSTN are avoided when calls are routed over the PSTN. Read more
On December 1st, Cisco announced changes to the CCIE Voice program that will take place some time in July 2009.
The new CCIE Voice will no longer include the following hardware:
Catalyst 6000 / 6608-T1 gateway module
ATA-186
VG248
The new CCIE Voice will use the 7.0 versions of the following Cisco Unified Communications software:
Cisco Unified Communications Manager Read more
Cisco Unified Communications Manager Express
Cisco Unity Express (NME-CUE)
Cisco Unified Contact Center Express
Cisco Unified Presence
Cisco Unity Connection (no more Cisco Unity)
Cisco Unified Communications Manager (CUCM) has the following four deployment models which we will begin discussing in this blog series:
• Single Site Read more
• Centralized
• Distributed
• Clustering over the WAN
The Account configuration page of the subscriber templates can be used to lock the TUI access of a Unity subscriber or to configure the billing ID of a subscriber. The billing subscriber ID can be used in Unity subscriber reports.
PASSWORDS
The passwords configuration of the subscriber template is as follows:
• User cannot change password Read more
• User must change password at next login
• Password never expires
• Phone password for new subscribers (default from UTIM password hardening wizard)
In this blog, we will cover the subscriber template configurations. Subscriber templates are only applied to subscribers when they are first added to the Cisco Unity system. After a subscriber has been created, changes to a subscriber template will not apply to any Unity subscribers that were created with the changed subscriber template. Subscriber’s features and options can be managed individually on the Unity system administrator (SA) configuration pages. Read more
This blog continues our coverage of the class of service configuration in Cisco Unity 5.0. Cisco Unity has two default classes of service: Default Administrator and Default Subscriber. Any defaults mentioned apply to the Default Subscriber class of service.
MESSAGES
Most of the message configuration options are very self explanatory. The deleted messages option allows a subscriber to undelete deleted voicemail messages.
• Maximum length of message subscribers can record, in seconds (300 by default) Read more
The class of service configuration of Cisco Unity controls the features available to the subscribers associated with the class of service. The class of service configuration in Cisco Unity 5.0 has eight sub configuration options as follows:
• Profile
• Subscribers
• System Access
• Transfer
• Messages
• Greetings
• Features
• Restriction Tables
We will take a look at each menu’s configuration items. Most of the options are self explanatory, but I will cover them if they are not straightforward. If you have any questions, feel free to ask.
PROFILE Read more
In preparation for adding subscribers into the Cisco Unity system, the following settings should first be configured:
• Account Policy
• System Schedule
• Public Distribution List
• Class of Service
• Subscriber Template
The Unity account policy controls the password restrictions and lockout policy (Subscribers > Account Policy). The phone password restrictions include the following parameters:
• Password expiration policy (in days) Read more
• Minimum TUI password length
• Phone password complexity (uniqueness)
Microsoft Active Directory has to be properly setup with the necessary permissions for the four critical users. The Cisco Unity Syscheck tool is used to verify the system is setup properly before installing Cisco Unity. The Cisco Unity setup.exe program executes the Cisco Unity Installation and Configuration Assistant (CUICA) tool which is a seven step configuration utility. The seven steps of CUICA are as follows:
1. Install Cisco Unity Read more
2. Install the Cisco Unity License Files
3. Configure the Cisco Unity Services
4. Configure the Cisco Unity Message Store
There is a critical bug in versions 5.0.x, 5.1.x, 6.0.x, and 6.1.x that will crash the Call Manager and CTI Manager services on the CUCM server after 248 consecutive days of uptime. For full information including patches and workarounds; read the Cisco Field Notice at the following URL: http://www.cisco.com/en/US/ts/fn/631/fn63174.html
The last blog covered some of the CUCM configuration elements required to integrate with Cisco Unity. This blog will cover the Unity setup required to integrate with Cisco Unified Communications Manager (CUCM).
There are two important wizard based utilities used in Cisco Unity to walk engineers through the setup of the system. The Cisco Unity System Preparation Assistant (CUSPA) is run on the Cisco Unity server after Windows 2003 server has been installed. CUSPA is a Microsoft Visual Basic script (CUSPA.vbs) that walks the installer through the setup of the following applications: Read more
Cisco Unity can be integrated with Cisco Unified Communications Manager over IP infrastructures using Cisco’s proprietary Skinny Client Control Protocol (SCCP) or Session Initiation Protocol (SIP). Cisco Unity can also be integrated with legacy voicemail solutions via PIMG (PBX IP Media Gateway) or TIMG (TDM IP Media Gateways) devices. Earlier versions of Cisco Unity supported Dialogic PCI expansion cards for traditional (TDM) PBX integrations, but Cisco stopped supporting the Dialogic PCI cards beginning with their support of the Windows 2003 server operating system. Read more
Cisco Unity and Cisco Unity Connections have three different user interfaces. The interfaces are commonly referred to as the TUI, GUI, and VUI. TUI stands for the telephone user interface and represents the options available via the buttons on the phone (1-9, *, and #). The TUI interface results in dual tone multi-frequency digits (DTMF) in traditional telephony. Forwarding digits in voice over IP, is referred to as DTMF-Relay. DTMF-Relay mechanisms are not turned on by default in VoIP dial-peers configured on Cisco H.323 or SIP gateways. Read more
Dennis Hartmann, CCIE No. 15651, is a Unified Communications consultant and author of Implementing Cisco Unified Communications Manager, Part 1. Dennis is also a lead instructor at Global Knowledge. Dennis was first exposed to CallManager during the CallManager 2.0 time frame when Cisco acquired Selsius. Dennis has various certifications, including the Cisco CCVP, CCSI, CCNP, CCIP, and the Microsoft MCSE. Dennis has worked for various Fortune 500 companies, including AT&T, Sprint, Merrill Lynch, KPMG, and Cabletron Systems. He lives with his wife and children in Hopewell Junction, New York.
Check out the Cisco course catalog from Global Knowledge.
The opinions expressed in this Weblog are those of the writer and may not represent the opinions of Network World.
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