Cisco to use SNA as weapon in carrier equipment battle
nwfusion.com
By Jim Duffy
Network World Fusion, 8/5/98
Cisco Systems' plan to use SNA as a
competitive advantage over Lucent
Technologies and Nortel hinges on providing
acceptable response time for the IBM data in a
multiservice IP network.
Cisco believes its experience in melding SNA
and IP internetworks can be used as a weapon
in the company's battle with Lucent and Nortel
for leadership in converging voice, video and
data over IP networks. SNA is a unique
component in Cisco's enterprise network
repertoire that the telecom giants cannot match,
the company claims.
"We're going to use that big-time against Lucent
and Nortel," said Frank Maly, director of
marketing for Cisco's Interworks business unit.
Lucent has virtually no experience in SNA
internetworking; Nortel is about to inherit some
when its multibillion dollar acquisition of Bay
Networks goes through. But Bay had just over
5% market share in SNA routers last year,
compared with Cisco's almost 80%, according
to International Data Corp. in Framingham,
Mass.
Nevertheless, Cisco's challenge will be to ensure
that SNA data does not get shortchanged on
bandwidth when it's running over the same
network as voice, video and IP data, commonly
referred to as a multiservice network. Cisco
must do this while at the same time providing
adequate response time for delay-sensitive voice
and video traffic.
To do this, Cisco first will encourage users to
converge their SNA and IP networks, and run
SNA encapsulated in IP packets. Cisco will
then allow users to set IP precedence bits in the
headers of those packets to establish priority,
bandwidth reservation and other class- and
quality-of-service (QoS) characteristics for
SNA data.
Cisco has performed internal tests of SNA
response time over multiservice nets using the
QoS features of Cisco IOS, including priority
queuing, custom queuing and the Resource
Reservation Protocol. The tests included Cisco's
4500 and 3600 routers with voice-over-IP
cards, the company's IP/TV multimedia
application on Windows NT 4.0, and
Ganymede Software's Chariot SNA and
Chariot IP applications.
The tests simulated 10 to 20 SNA interactive
users in one transaction per minute in which
100-byte requests initiated 1,500-byte
responses. Those sessions contended for
bandwidth with 12K bit/sec voice on a 64K
bit/sec link, 1.5M bit/sec MPEG video and
audio, and between 10 and 80 competing File
Transfer Protocol (FTP) file transfers.
Congestion occurred on the outbound - central
to remote - 64K bit/sec and T-1 links.
Over a 64K bit/sec link with 20 FTP sessions,
Cisco claims to have maintained subsecond
SNA response time. Voice/telephony and IP file
transfers also performed within specifications,
Maly said. Cisco will unveil hardware and
software over time that allow users to establish
SNA class of service and QoS policies for
multiservice networks, Maly said. One such
product is Version 2.0 of Cisco IOS for S/390
software, which allows users to set IP
precedence bits for SNA traffic
. Cisco may also extend voice support to its
7500 and 12000 series routers, and Catalyst
8500 switching routers.
"We will have high-end equipment that will be
the head-end of voice [networks]," Maly said.
These devices will strip the voice out of an IP
packet, he said. |
