Enterprise QoS Solution Reference Network Design Guide

Chapter 1 Quality of Service Design Overview
QoS Requirements of the Control Plane
IP Routing
Version 3.3
Table 1-4 Data Applications by Class
Transactional SAP, PeopleSoft (Vantive)
Oracle—financials, Internet
procurement, B2B, supply chain
management, and application
server
Oracle 8i Database
Ariba Buyer
I2, Siebel, E.piphany
Broadvision
IBM Bus 2 Bus
Microsoft SQL
BEA Systems
DLSw+
Bulk Database syncs
Network-based backups
Lotus Notes, Microsoft Outlook
E-mail download (SMTP, POP3,
IMAP, Exchange)
Video content distribution,
Large ftp file transfers
Best-Effort All non-critical traffic
HTTP Web browsing + other
miscellaneous traffic
How is QoS Optimally Deployed within the Enterprise?
Transactional applications
typically use a client-server
protocol model.
User initiated client-based
queries followed by server
response. Query response
may consist of many
messages between client and
server.
Query response may consist
of many TCP and FTP
sessions running
simultaneously (for example,
HTTP based applications)
Long file transfers
Always invokes TCP
congestion management
This section includes the following topics:
IP Routing
Network Management
Unless the network is up and running, QoS is irrelevant. Therefore, it is critical to provision QoS for
control plane traffic, which includes IP Routing traffic and Network Management.
By default, Cisco IOS software (in accordance with RFC 791 and RFC 2474) marks Interior Gateway
Protocol (IGP) traffic such as Routing Information Protocol (RIP/RIPv2), Open Shortest Path First
(OSPF), and Enhanced Interior Gateway Routing Protocol (EIGRP) to DSCP CS6. However, Cisco IOS
software also has an internal mechanism for granting internal priority to important control datagrams as
they are processed within the router. This mechanism is called PAK_PRIORITY.
Enterprise QoS Solution Reference Network Design Guide
Depends on
application—could be
anywhere from 1 KB
to 50 MB
Average message size
64 KB or greater
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