Table Of Contents

Quality of Service "QoS"

Technology Description

Quality of Service (QoS)

Inventory and Information Model Objects (IMOs)

Access List Traffic Descriptor

Access List Entry

Network Topology

Service Alarms

Quality of Service "QoS"

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This chapter describes the level of support that Cisco ANA provides for QoS, as follows:

•Technology Description

•Inventory and Information Model Objects (IMOs)

•Network Topology

•Service Alarms

Technology Description

Quality of Service (QoS)

Quality of Service (QoS) refers to the capability of a network to provide better service to selected network traffic over various technologies, including Frame Relay, Asynchronous Transfer Mode (ATM), Ethernet and 802.1 networks, SONET, and IP-routed networks that may use any or all of these underlying technologies. The primary goal of QoS is to provide priority including dedicated bandwidth, controlled jitter and latency (required by some real time and interactive traffic), and improved loss characteristics. Also important is making sure that providing priority for one or more flows does not make other flows fail. Integrated and Differentiated Service (IS/DS) are the two model currently being use for providing QoS.

Integrated Service (IS) is a multiple service model that can accommodate multiple QoS requirements. In this model the application requests a specific kind of service from the network before it sends data. The request is made by explicit signalling; the application informs the network of its traffic profile and requests a particular kind of service that can encompass its bandwidth and delay requirements. The application is expected to send data only after it gets a confirmation from the network. It is also expected to send data that lies within its described traffic profile.

The network performs admission control, based on information from the application and available network resources. It also commits to meeting the QoS requirements of the application as long as the traffic remains within the profile specifications. The network fulfills its commitment by maintaining per flow state and then performing packet classification, policing, and intelligent queuing based on that state.

Differentiated Service (DS) is a multiple service model that can satisfy differing QoS requirements. However, unlike in the integrated service model, an application using differentiated service does not explicitly signal the router before sending data. For differentiated service, the network tries to deliver a particular kind of service based on the QoS specified by each packet. This specification can occur in different ways, for example, using the IP Precedence bit settings in IP packets or source and destination addresses. The network uses the QoS specification to classify, mark, shape, and police traffic, and to perform intelligent queuing.

Inventory and Information Model Objects (IMOs)

This section currently describes Cisco's Quality of Service (QoS) objects, although they may appear to be generic QoS objects that may be used by other vendors.

This section includes the following tables:

•Access List Traffic Descriptor (IAccessList)

•Access List Entry (IAccessListEntry)

Access List Traffic Descriptor

The following Access List Traffic Descriptor with its Access List Entry objects describes the access list of a single type (Unknown, Standard, Extended and Rate Limit), and is being aggregated by a Traffic Descriptor Container object (see Common (Shared by Several)).

Table 16-1 Access List Traffic Descriptor (IAccessList)

Attribute Name	Attribute Description
Type	Access list type (Unknown, Standard, Extended, Rate Limit)
Access List Entries Table	Array of Access List Entries
Name	Traffic descriptor name
Index	Traffic descriptor index

Access List Entry

Table 16-2 Access List Entry (IAccessListEntry) 

Attribute Name	Attribute Description
Entry Identification	Entry identification
Action Logic	Action logic (Unknown, Permit, Deny)
Source and Destination Address	Source and destination IP address
Source and Destination Wildcard	Source and destination IP wildcard
Protocol Type	IANA type of the protocol (HOPORT, ICMP, IGMP, GGP, IP in IP, ST, TCP, CBT, EGP, IGP, ...)
Source and Destination Ports Ranges	Source and destination TCP/UDP ports ranges
Source and Destination Port Action	Source and destination port action (Null, Equal, Not Equal, Greater Than, Less Than, Range)
Protocol Specific Info	Protocol specific information
Differential Services Code Points	Differential Services Code Points (DSCP)
Type of Service	Type of Service (ToS) (Normal (0), Min Cost (1), Max Reliability (2), 3, Max Throughput (4), 5, 6, 7, Min Delay (8), 9, 10, 11, 12, 13, 14, 15)
Precedence	Precedence (Routine (0), Priority (1), Immediate (2), Flash (3), Flash Override (4), Critical (5), Internet (6), Network (7))
Matches	Matches count

Network Topology

There is no network topology related to this technology.

Service Alarms

There are no faults and alarms related to this technology.