F1000-AK108

现情况为北京与四川做IPSEC VPN（北京设备为江南信安，四川设备为华三AK108），隧道建立成功，并能转发数据，但是存在丢包现象。

现在有一个不能理解的问题，北京的内网为10.18.80.0段，在四川侧防火墙上不带源ping可以ping通10.18.80.1，tracert此地址的结果数据为

1 111.9.152.1 (111.9.152.1) 2.444 ms 1.960 ms 1.764 ms 

 2 221.182.116.137 (221.182.116.137) 3.842 ms 221.182.116.133 (221.182.116.133) 3.775 ms 3.471 ms 

 3 223.87.25.17 (223.87.25.17) 3.064 ms 3.123 ms 223.87.25.13 (223.87.25.13) 4.615 ms 

 4 223.87.25.110 (223.87.25.110) 10.586 ms 223.87.25.114 (223.87.25.114) 11.939 ms 11.443 ms 

 5 10.18.80.1 (10.18.80.1) 14.717 ms 12.710 ms 13.209 ms

倒数第二跳的位置是达州

dis ipsec statistics tunnel-id 0 的信息如下

 IPsec packet statistics: Received/sent packets: 64305/90258 Received/sent bytes: 9353424/10642944 Dropped packets (received/sent): 0/0 Dropped packets statistics No available SA: 0 Wrong SA: 0 Invalid length: 0 Authentication failure: 0 Encapsulation failure: 0 Decapsulation failure: 0 Replayed packets: 0 ACL check failure: 0 MTU check failure: 0 Loopback limit exceeded: 0 Crypto speed limit exceeded: 0

请问这是什么情况，与VPN丢包是否有关系。