user manual
Table Of Contents
- Cisco ONS 15454 SDH Reference Manual
- Contents
- About this Guide
- Shelf and FMEC Hardware
- Common Control Cards
- Electrical Cards
- Optical Cards
- Ethernet Cards
- Storage Access Networking Cards
- Card Protection
- Cisco Transport Controller Operation
- Security and Timing
- Circuits and Tunnels
- SDH Topologies and Upgrades
- CTC Network Connectivity
- Alarm Monitoring and Management
- Ethernet Operation
- Hardware Specifications
- A.1 Shelf Specifications
- A.2 SFP Specifications
- A.3 General Card Specifications
- A.4 Common Control Card Specifications
- A.5 Electrical Card and FMEC Specifications
- A.5.1 E1-N-14 Card Specifications
- A.5.2 E1-42 Card Specifications
- A.5.3 E3-12 Card Specifications
- A.5.4 DS3i-N-12 Card Specifications
- A.5.5 STM1E-12 Card Specifications
- A.5.6 BLANK Card
- A.5.7 FMEC-E1 Specifications
- A.5.8 FMEC-DS1/E1 Card Specifications
- A.5.9 FMEC E1-120NP Card Specifications
- A.5.10 FMEC E1-120PROA Card Specifications
- A.5.11 FMEC E1-120PROB Card Specifications
- A.5.12 E1-75/120 Impedance Conversion Panel Specifications
- A.5.13 FMEC-E3/DS3 Card Specifications
- A.5.14 FMEC STM1E 1:1 Card Specifications
- A.5.15 FMEC-BLANK Card Specifications
- A.5.16 MIC-A/P Card Specifications
- A.5.17 MIC-C/T/P Card Specifications
- A.6 Optical Card Specifications
- A.6.1 OC3 IR 4/STM1 SH 1310 Card Specifications
- A.6.2 OC3 IR/STM1 SH 1310-8 Card Specifications
- A.6.3 OC12 IR/STM4 SH 1310 Card Specifications
- A.6.4 OC12 LR/STM4 LH 1310 Card Specifications
- A.6.5 OC12 LR/STM4 LH 1550 Card Specifications
- A.6.6 OC12 IR/STM4 SH 1310-4 Card Specifications
- A.6.7 OC48 IR/STM16 SH AS 1310 Card Specifications
- A.6.8 OC48 LR/STM16 LH AS 1550 Card Specifications
- A.6.9 OC48 ELR/STM16 EH 100 GHz Card Specifications
- A.6.10 OC192 SR/STM64 IO 1310 Card Specifications
- A.6.11 OC192 IR/STM64 SH 1550 Card Specifications
- A.6.12 OC192 LR/STM64 LH 1550 Card Specifications
- A.6.13 OC192 LR/STM64 LH ITU 15xx.xx Card Specifications
- A.7 Ethernet Card Specifications
- A.8 Storage Access Networking Card Specifications
- Administrative and Service States
- Network Element Defaults
- Index

12-17
Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter 12 CTC Network Connectivity
12.2.8 Scenario 8: Dual GNEs on a Subnet
If the packet is addressed to the ONS 15454 SDH, additional rules shown in Table 12-4 apply. Rejected
packets are silently discarded.
If you implement the proxy server, keep the following rules in mind:
• All DCC-connected ONS 15454 SDH nodes on the same Ethernet segment must have the same
Craft Access Only setting. Mixed values produce unpredictable results, and might leave some nodes
unreachable through the shared Ethernet segment.
• All DCC-connected ONS 15454 SDH nodes on the same Ethernet segment must have the same
Enable Firewall setting. Mixed values produce unpredictable results. Some nodes might become
unreachable.
• If you check Enable Firewall, always check Enable Proxy. If Enable Proxy is not checked, CTC
cannot see nodes on the DCC side of the ONS 15454 SDH.
• If Craft Access Only is checked, check Enable Proxy. If Enable Proxy is not checked, CTC cannot
see nodes on the DCC side of the ONS 15454 SDH.
If nodes become unreachable in cases 1, 2, and 3, you can correct the setting by performing one of the
following:
• Disconnect the craft computer from the unreachable ONS 15454 SDH. Connect to the
ONS 15454 SDH through another ONS 15454 SDH in the network that has a DCC connection to the
unreachable ONS 15454 SDH.
• Disconnect the Ethernet cable from the unreachable ONS 15454 SDH. Connect a CTC computer
directly to the ONS 15454 SDH.
12.2.8 Scenario 8: Dual GNEs on a Subnet
The ONS 15454 SDH provides GNE load balancing, which allows CTC to reach ENEs over multiple
GNEs without the ENEs being advertised over OSPF. This feature allows a network to quickly recover
from the loss of GNE, even if the GNE is on a different subnet. If a GNE fails, all connections through
that GNE fail. CTC disconnects from the failed GNE and from all ENEs for which the GNE was a proxy,
and then reconnects through the remaining GNEs. GNE load balancing reduces the dependency on the
launch GNE and DCC bandwidth, both of which enhance CTC performance. Figure 12-14 shows a
network with dual GNEs on the same subnet.
Table 12-4 Proxy Server Firewall Filtering Rules When Packet Addressed to ONS 15454 SDH
Packets Arriving At Accepts Rejects
TCC2/TCC2P
Ethernet interface
• All UDP packets except those in
the Rejected column
• UDP packets addressed to the
SNMP trap relay port (391)
DCC interface
• All UDP packets
• All TCP packets except those in
the Rejected column
• OSPF packets
• ICMP packets
• TCP packets addressed to the
Telnet port
• TCP packets addressed to the
proxy server port
• All packets other than UDP, TCP,
OSPF, and ICMP.