Why Choose Singtel Cn2 As Your Preferred Solution For International Links?

1.

overview: why singapore’s export cn2 link is prioritized

china telecom cn2 connected to singapore (that is, the cn2 dedicated line with pop in singapore) is selected as the international main link. the main goal is stability, low jitter and better interconnection quality to mainland china and the asia-pacific. this paragraph outlines the decision logic: low latency, low packet loss rate, cn2 is friendly to routes within china, and requires less detours when connecting to mainland operators. the following paragraphs give practical steps.

2.

preparation work and prerequisites

list the necessary preparation items: 1) clarify the exit point (singapore pop) and target traffic (to china or other countries); 2) prepare asn, prefix to be announced (/24 or shorter policy) and contact information; 3) evaluate the cabinet/delivery port (10ge/1ge); 4) confirm budget and sla requirements; 5) test tools (external network machine, mtr, ping, traceroute, iperf3).

3.

step one: link front-end quality test (implemented in singapore cn2 )

practical operations: 1) find or rent a vps/test machine in singapore (vultr, alibaba cloud singapore, etc. can be used); 2) execute mtr -c 100 -r -w <target ip> from your source point to record packet loss and average delay; 3) use traceroute -n to the target, paying attention to the asn path (check whether it passes through cn2 asn such as 4812/4134, etc.); 4) use iperf3 to measure speed (iperf3 -c <singapore server> -t 60) verify bandwidth stability; 5) save data for multiple time periods as csv to compare operator samples.

4.

step two: supplier screening and inquiry process

step by step: 1) list the operators/agents (such as china telecom international/direct connect agent) that can provide "cn2 singapore export" or "cn2 to singapore direct connection"; 2) submit an inquiry form: describe the port speed, one-way delay target, peak bandwidth, backup link requirements and sla (availability rate 99.95+, rto/rpo); 3) require pop information, bgp session parameters, physical delivery time; 4) request a test account or temporary link for a/b testing.

5.

step 3: sign the contract and place the order (note the terms)

practical notes: 1) confirm the delivery period and penalty terms (sli/sla); 2) clarify the maintenance window, noc contact information and time zone; 3) determine whether ip transit (with public network egress) or only l2/l3 dedicated line is required; 4) require the operator to open bgp peering, and write the routing policy or allow community tag; 5) save the contract, po and engineering contact after signing.

6.

step 4: on-site delivery and physical connectivity verification

steps: 1) after receiving the operator port and delivery document (vlan, port number, speed), connect to the local router and connect to the link; 2) configure the physical interface (example cisco: interface tengige0/1 description cn2-sg no shutdown switchport trunk allowed vlan... or router bgp ); 3) do link layer detection first: ethtool/ifconfig/ip link show; 4) use ping <peer gateway> to verify l2/l3 connectivity.

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step 5: bgp session establishment and routing policy configuration (example)

example steps (cisco ios): 1) router bgp <your asn> neighbor <peer ip> remote-as <peer asn> description "cn2-sg"; 2) configure password (optional); 3) publish prefix: network <your prefix> mask <mask> or declare with route-map; 4) limit the number of prefixes received/published by the peer; 5) use route-map to set local-preference, med or community prefer cn2; example command: route-map set_localp permit 10 set local-preference 200.

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step 6: peering and routing optimization strategy (prefer cn2’s specific strategy)

operation points: 1) set a high local-preference for the cn2 route (set local-preference 200 in the local route-map of the neighbor); 2) set a lower priority for other backup links; 3) use as-path or community to identify the operator and perform blacklist filtering; 4) test switching: verify whether the traffic switching is as expected by adjusting local-pref or shutdown neighbor.

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step seven: tunnel/encrypted backup and mpls vpn configuration

steps: 1) if it is impossible to establish a physical dedicated line or you want to diversify, you can establish an ipsec or gre over ipsec tunnel between singapore cn2 and the local area; 2) configuration example (strongswan/openssl): generate a certificate, configure ipsec.conf, and establish ikev2; 3) if the operator supports mpls vpn, l3vpn is required and route distinguisher/rt is required, configure vrf and import and export routes; 4) verify tunnel packet loss/bandwidth and set traffic policy (such as critical-apps through cn2, backup through other links).

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step 8: monitoring, alerts and continuous optimization

practical operations: 1) deployment monitoring: use zabbix/prometheus + black box probe to perform ping/mtr/iperf tests on targets regularly; 2) set up sla reports (30 minutes/hour/day data); 3) configure alarms (packet loss >1%, rtt exceeds threshold) to the email/sms/work order system; 4) analyze routing tables, bgp convergence time and packet loss windows monthly, and optimize together with operators.

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step 9: fault drill and automatic switching

steps: 1) develop a fault drill plan (simulating a cn2 failure) and record the switch time and impact; 2) automatic switch: use bgp traffic engineering (local-pref/as-path prepend) or sd-wan/router scripts (automatically modify route-map based on monitoring events) to achieve automation; 3) adjust the playbook and alarm thresholds after the drill.

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step 10: safety, compliance and daily operation and maintenance precautions

practical points: 1) restrict bgp session source ip and enable md5 password; 2) perform rpki/roa verification and prefix filtering on advertised prefixes; 3) enable acl/firewall at the edge to prevent ddos; 4) regularly review routing tables and access logs with operators.

13.

faq 1: why should we use cn2 instead of ordinary international forwarding links?

answer: cn2 usually provides shorter paths, dedicated bearers and better interconnection quality to mainland china. packet loss and delay are more controllable. it is suitable for services with high requirements on delay and stability, such as games, voice, financial transactions, etc. at the same time, cn2 operators usually provide clearer slas.

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faq 2: how to truly ensure that traffic goes through cn2 instead of the backup link in bgp?

answer: set a higher local-preference for the cn2 peer in the local routing policy, and add as-path prepend or a lower local-preference for the backup line; in addition, you can use bgp community tags or med to coordinate peer preferences. the test is conducted through shutdown/adjustment of priorities to ensure that the policy takes effect.

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faq 3: what are the key risks of deploying cn2 links and how to avoid them?

a: risks include supplier delivery delays, bgp leaks, single points of failure, and increased costs. avoidance methods: sign a clear sla, prepare backup links (not the same operator or different physical paths), implement strict prefix filtering and rpki, conduct regular fault drills and respond quickly with monitoring alarms.