Cisco 2950 - Catalyst Switch 데이터시트 - 페이지 4

{카테고리_이름} Cisco 2950 - Catalyst Switch에 대한 데이터시트을 온라인으로 검색하거나 PDF를 다운로드하세요. Cisco 2950 - Catalyst Switch 20 페이지. Long-reach ethernet switches
Cisco 2950 - Catalyst Switch에 대해서도 마찬가지입니다: 솔루션 매뉴얼 (17 페이지), 제품 게시판 (3 페이지), 제품 지원 게시판 (5 페이지), 마이그레이션 매뉴얼 (25 페이지), 제품 지원 게시판 (6 페이지), 시작하기 매뉴얼 (29 페이지), 매뉴얼 (19 페이지)

Controller Access Control System (TACACS+) or RADIUS server, 802.1x provides port-level security. SNMPv3

(non-crypto) monitors and controls network devices as well as manages conﬁgurations, performance, collection of

statistics and security.

With the multi-layer Cisco Catalyst 2950 LRE switches, network managers can implement high levels of console

security. Multilevel access security on the switch console and the web-based management interface prevents

unauthorized users from accessing or altering switch conﬁguration TACACS+ or RADIUS authentication enables

centralized access control of the switch and restricts unauthorized users from altering the conﬁguration. Deploying

security can be done through Cisco CMS Software Security Wizards, which ease the deployment of security features

that restrict user access to a server, a portion of the network, or access to the network.

Network Control through Advanced Quality of Service and Rate Limiting

The Catalyst 2950 LRE Series switches offer superior and highly granular QoS based on Layer 2-4 information, to

ensure that network trafﬁc is classiﬁed, prioritized, and congestion is avoided in the best possible manner. The Catalyst

2950 LRE Series switches can classify, reclassify, police (determine if the packet is in or out of predetermined proﬁles

and affect actions on the packet), and mark or drop the incoming packets before the packet is placed in the shared

buffer. Packet classiﬁcation allows the network elements to discriminate between various trafﬁc ﬂows and enforce

policies based on Layer 2 and Layer 3 QoS ﬁelds.

To implement QoS, these switches ﬁrst identify trafﬁc ﬂows, or packet groups, and classify or reclassify these groups

using the DiffServ Code Point ﬁeld (DSCP) in the IP packet and/or the 802.1p class of service (CoS) ﬁeld in the

Ethernet packet. Classiﬁcation and reclassiﬁcation can also be based on criteria as speciﬁc as the source/destination

IP address, source/destination MAC address or the Layer 4 Transmission Control Protocol (TCP)/User Datagram

Protocol (UDP) ports. At the ingress (incoming port) level, the Catalyst switches will also perform policing and

marking of the packet.

After the packet goes through classiﬁcation, policing, and marking, it is then assigned to the appropriate queue before

exiting the switch. The Catalyst 2950 LRE Series switches support four egress (outgoing port) queues per port, which

allows the network administrator to be more discriminating and speciﬁc in assigning priorities for the various

applications on the LAN. At the egress level, the switch performs scheduling, which is an algorithm/process that

determines the order in which the queues are processed. The switches support Weighted Round Robin (WRR)

scheduling or strict priority scheduling. The WRR scheduling algorithm ensures that the lower priority packets are

not entirely starved for bandwidth and are serviced without compromising the priority settings administered by the

network manager. Strict priority scheduling ensures that the highest priority packets will always get serviced ﬁrst,

ahead of all other trafﬁc, and that the other three queues will be serviced using WRR best effort.

These features allow network administrators to prioritize mission-critical and/or bandwidth-intensive trafﬁc, such

as ERP (Oracle, SAP, and so on), voice (IP telephony trafﬁc) and CAD/CAM over less time-sensitive applications

such as FTP or e-mail (SMTP). For example, it would be highly undesirable to have a large ﬁle download destined

to one port on a wiring closet switch and have quality implications such as increased latency in voice trafﬁc, destined

to another port on this switch. This condition is avoided by ensuring that voice trafﬁc is properly classiﬁed and

prioritized throughout the network. Other applications, such as web browsing, can be treated as low priority and

handled on a best-efforts basis.

Cisco Systems, Inc.

Page 4 of 19